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677 lines
19 KiB
677 lines
19 KiB
/*
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* Copyright (C) 2004 Tomasz Kojm <tkojm@clamav.net>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#if HAVE_CONFIG_H
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#include "clamav-config.h"
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#endif
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#include <stdio.h>
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#include <string.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <sys/stat.h>
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#include <unistd.h>
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#include <time.h>
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#include "cltypes.h"
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#include "clamav.h"
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#include "others.h"
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#include "pe.h"
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#include "upx.h"
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#include "petite.h"
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#include "scanners.h"
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#define IMAGE_DOS_SIGNATURE 0x5a4d /* MZ */
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#define IMAGE_DOS_SIGNATURE_OLD 0x4d5a /* ZM */
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#define IMAGE_NT_SIGNATURE 0x00004550
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#define IMAGE_OPTIONAL_SIGNATURE 0x010b
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#define DETECT_BROKEN (options & CL_BROKEN)
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#define UPX_NRV2B "\x11\xdb\x11\xc9\x01\xdb\x75\x07\x8b\x1e\x83\xee\xfc\x11\xdb\x11\xc9\x11\xc9\x75\x20\x41\x01\xdb"
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#define UPX_NRV2D "\x83\xf0\xff\x74\x78\xd1\xf8\x89\xc5\xeb\x0b\x01\xdb\x75\x07\x8b\x1e\x83\xee\xfc\x11\xdb\x11\xc9"
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#define UPX_NRV2E "\xeb\x52\x31\xc9\x83\xe8\x03\x72\x11\xc1\xe0\x08\x8a\x06\x46\x83\xf0\xff\x74\x75\xd1\xf8\x89\xc5"
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#if WORDS_BIGENDIAN == 0
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#define EC16(v) (v)
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#define EC32(v) (v)
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#else
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static inline uint16_t EC16(uint16_t v)
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{
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return ((v >> 8) + (v << 8));
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}
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static inline uint32_t EC32(uint32_t v)
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{
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return ((v >> 24) | ((v & 0x00FF0000) >> 8) | ((v & 0x0000FF00) << 8) | (v << 24));
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}
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#endif
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extern short cli_leavetemps_flag;
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static uint32_t cli_rawaddr(uint32_t rva, struct pe_image_section_hdr *shp, uint16_t nos)
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{
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int i, found = 0;
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for(i = 0; i < nos; i++) {
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if(EC32(shp[i].VirtualAddress) <= rva && EC32(shp[i].VirtualAddress) + EC32(shp[i].SizeOfRawData) > rva) {
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found = 1;
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break;
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}
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}
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if(!found) {
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cli_dbgmsg("Can't calculate raw address from RVA 0x%x\n", rva);
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return -1;
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}
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return rva - EC32(shp[i].VirtualAddress) + EC32(shp[i].PointerToRawData);
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}
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static int cli_ddump(int desc, int offset, int size, const char *file)
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{
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int pos, ndesc, bread, sum = 0;
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char buff[FILEBUFF];
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cli_dbgmsg("in ddump()\n");
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if((pos = lseek(desc, 0, SEEK_CUR)) == -1) {
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cli_dbgmsg("Invalid descriptor\n");
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return -1;
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}
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if(lseek(desc, offset, SEEK_SET) == -1) {
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cli_dbgmsg("lseek() failed\n");
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lseek(desc, pos, SEEK_SET);
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return -1;
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}
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if((ndesc = open(file, O_WRONLY|O_CREAT|O_TRUNC, S_IRWXU)) < 0) {
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cli_dbgmsg("Can't create file %s\n", file);
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lseek(desc, pos, SEEK_SET);
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return -1;
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}
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while((bread = read(desc, buff, FILEBUFF)) > 0) {
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if(sum + bread >= size) {
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if(write(ndesc, buff, size - sum) == -1) {
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cli_dbgmsg("Can't write to file\n");
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lseek(desc, pos, SEEK_SET);
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close(ndesc);
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unlink(file);
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return -1;
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}
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break;
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} else {
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if(write(ndesc, buff, bread) == -1) {
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cli_dbgmsg("Can't write to file\n");
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lseek(desc, pos, SEEK_SET);
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close(ndesc);
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unlink(file);
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return -1;
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}
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}
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sum += bread;
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}
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close(ndesc);
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lseek(desc, pos, SEEK_SET);
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return 0;
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}
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int cli_memstr(const char *haystack, int hs, const char *needle, int ns)
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{
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const char *pt;
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int n;
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if(!memcmp(haystack, needle, ns))
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return 1;
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pt = haystack;
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n = hs;
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while(n && (pt = memchr(pt, needle[0], n))) {
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n--;
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if(!memcmp(pt, needle, ns))
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return 1;
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}
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return 0;
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}
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int cli_scanpe(int desc, const char **virname, long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options, int *arec, int *mrec)
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{
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uint16_t e_magic; /* DOS signature ("MZ") */
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uint16_t nsections;
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uint32_t e_lfanew; /* address of new exe header */
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uint32_t ep; /* entry point (raw) */
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time_t timestamp;
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struct pe_image_file_hdr file_hdr;
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struct pe_image_optional_hdr optional_hdr;
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struct pe_image_section_hdr *section_hdr;
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struct stat sb;
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char sname[9], buff[256], *tempfile;
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int i, found, upx_success = 0, broken = 0, min = 0, max = 0;
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int (*upxfn)(char *, int , char *, int) = NULL;
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char *src, *dest;
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int ssize, dsize, ndesc;
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if(read(desc, &e_magic, sizeof(e_magic)) != sizeof(e_magic)) {
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cli_dbgmsg("Can't read DOS signature\n");
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return CL_EIO;
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}
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if(EC16(e_magic) != IMAGE_DOS_SIGNATURE && EC16(e_magic) != IMAGE_DOS_SIGNATURE_OLD) {
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cli_dbgmsg("Invalid DOS signature\n");
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return CL_CLEAN;
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}
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lseek(desc, 58, SEEK_CUR); /* skip to the end of the DOS header */
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if(read(desc, &e_lfanew, sizeof(e_lfanew)) != sizeof(e_lfanew)) {
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cli_dbgmsg("Can't read new header address\n");
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return CL_EIO;
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}
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e_lfanew = EC32(e_lfanew);
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cli_dbgmsg("e_lfanew == %d\n", e_lfanew);
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if(!e_lfanew) {
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cli_dbgmsg("Not a PE file\n");
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return CL_CLEAN;
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}
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if(lseek(desc, e_lfanew, SEEK_SET) < 0) {
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/* probably not a PE file */
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cli_dbgmsg("Can't lseek to e_lfanew\n");
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return CL_CLEAN;
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}
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if(read(desc, &file_hdr, sizeof(struct pe_image_file_hdr)) != sizeof(struct pe_image_file_hdr)) {
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/* bad information in e_lfanew - probably not a PE file */
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cli_dbgmsg("Can't read file header\n");
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return CL_CLEAN;
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}
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if(EC32(file_hdr.Magic) != IMAGE_NT_SIGNATURE) {
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cli_dbgmsg("Invalid PE signature (probably NE file)\n");
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return CL_CLEAN;
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}
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switch(EC16(file_hdr.Machine)) {
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case 0x14c:
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cli_dbgmsg("Machine type: 80386\n");
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break;
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case 0x014d:
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cli_dbgmsg("Machine type: 80486\n");
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break;
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case 0x014e:
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cli_dbgmsg("Machine type: 80586\n");
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break;
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case 0x162:
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cli_dbgmsg("Machine type: R3000\n");
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break;
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case 0x166:
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cli_dbgmsg("Machine type: R4000\n");
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break;
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case 0x168:
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cli_dbgmsg("Machine type: R10000\n");
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break;
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case 0x184:
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cli_dbgmsg("Machine type: DEC Alpha AXP\n");
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break;
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case 0x1f0:
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cli_dbgmsg("Machine type: PowerPC\n");
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break;
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default:
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cli_warnmsg("Unknown machine type in PE header\n");
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}
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nsections = EC16(file_hdr.NumberOfSections);
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cli_dbgmsg("NumberOfSections: %d\n", nsections);
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timestamp = (time_t) EC32(file_hdr.TimeDateStamp);
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cli_dbgmsg("TimeDateStamp: %s", ctime(×tamp));
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cli_dbgmsg("SizeOfOptionalHeader: %d\n", EC16(file_hdr.SizeOfOptionalHeader));
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if(EC16(file_hdr.SizeOfOptionalHeader) != sizeof(struct pe_image_optional_hdr)) {
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cli_warnmsg("Broken PE header detected.\n");
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if(DETECT_BROKEN) {
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if(virname)
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*virname = "Broken.Executable";
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return CL_VIRUS;
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}
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return CL_CLEAN;
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}
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if(read(desc, &optional_hdr, sizeof(struct pe_image_optional_hdr)) != sizeof(struct pe_image_optional_hdr)) {
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cli_dbgmsg("Can't optional file header\n");
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if(DETECT_BROKEN) {
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if(virname)
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*virname = "Broken.Executable";
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return CL_VIRUS;
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}
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return CL_CLEAN;
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}
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cli_dbgmsg("MajorLinkerVersion: %d\n", optional_hdr.MajorLinkerVersion);
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cli_dbgmsg("MinorLinkerVersion: %d\n", optional_hdr.MinorLinkerVersion);
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cli_dbgmsg("SizeOfCode: %d\n", EC32(optional_hdr.SizeOfCode));
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cli_dbgmsg("SizeOfInitializedData: %d\n", EC32(optional_hdr.SizeOfInitializedData));
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cli_dbgmsg("SizeOfUninitializedData: %d\n", EC32(optional_hdr.SizeOfUninitializedData));
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cli_dbgmsg("AddressOfEntryPoint: 0x%x\n", EC32(optional_hdr.AddressOfEntryPoint));
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cli_dbgmsg("SectionAlignment: %d\n", EC32(optional_hdr.SectionAlignment));
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cli_dbgmsg("FileAlignment: %d\n", EC32(optional_hdr.FileAlignment));
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cli_dbgmsg("MajorSubsystemVersion: %d\n", EC16(optional_hdr.MajorSubsystemVersion));
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cli_dbgmsg("MinorSubsystemVersion: %d\n", EC16(optional_hdr.MinorSubsystemVersion));
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cli_dbgmsg("SizeOfImage: %d\n", EC32(optional_hdr.SizeOfImage));
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cli_dbgmsg("SizeOfHeaders: %d\n", EC32(optional_hdr.SizeOfHeaders));
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switch(EC16(optional_hdr.Subsystem)) {
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case 1:
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cli_dbgmsg("Subsystem: Native (a driver ?)\n");
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break;
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case 2:
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cli_dbgmsg("Subsystem: Win32 GUI\n");
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break;
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case 3:
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cli_dbgmsg("Subsystem: Win32 console\n");
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break;
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case 5:
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cli_dbgmsg("Subsystem: OS/2 console\n");
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break;
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case 7:
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cli_dbgmsg("Subsystem: POSIX console\n");
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break;
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default:
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cli_warnmsg("Unknown subsystem in PE header\n");
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}
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cli_dbgmsg("NumberOfRvaAndSizes: %d\n", EC32(optional_hdr.NumberOfRvaAndSizes));
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cli_dbgmsg("------------------------------------\n");
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section_hdr = (struct pe_image_section_hdr *) cli_calloc(nsections, sizeof(struct pe_image_section_hdr));
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if(!section_hdr) {
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cli_dbgmsg("Can't allocate memory for section headers\n");
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return CL_EMEM;
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}
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if(fstat(desc, &sb) == -1) {
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cli_dbgmsg("fstat failed\n");
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free(section_hdr);
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return CL_EIO;
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}
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for(i = 0; i < nsections; i++) {
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if(read(desc, §ion_hdr[i], sizeof(struct pe_image_section_hdr)) != sizeof(struct pe_image_section_hdr)) {
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cli_dbgmsg("Can't read section header\n");
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cli_dbgmsg("Possibly broken PE file\n");
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free(section_hdr);
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if(DETECT_BROKEN) {
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if(virname)
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*virname = "Broken.Executable";
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return CL_VIRUS;
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}
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return CL_CLEAN;
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}
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strncpy(sname, section_hdr[i].Name, 8);
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sname[8] = 0;
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cli_dbgmsg("Section %d\n", i);
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cli_dbgmsg("Section name: %s\n", sname);
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cli_dbgmsg("VirtualSize: %d\n", EC32(section_hdr[i].VirtualSize));
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cli_dbgmsg("VirtualAddress: 0x%x\n", EC32(section_hdr[i].VirtualAddress));
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cli_dbgmsg("SizeOfRawData: %d\n", EC32(section_hdr[i].SizeOfRawData));
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cli_dbgmsg("PointerToRawData: 0x%x (%d)\n", EC32(section_hdr[i].PointerToRawData), EC32(section_hdr[i].PointerToRawData));
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if(EC32(section_hdr[i].Characteristics) & 0x20) {
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cli_dbgmsg("Section contains executable code\n");
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if(EC32(section_hdr[i].VirtualSize) < EC32(section_hdr[i].SizeOfRawData)) {
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cli_dbgmsg("Section contains free space\n");
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/*
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cli_dbgmsg("Dumping %d bytes\n", section_hdr.SizeOfRawData - section_hdr.VirtualSize);
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ddump(desc, section_hdr.PointerToRawData + section_hdr.VirtualSize, section_hdr.SizeOfRawData - section_hdr.VirtualSize, cli_gentemp(NULL));
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*/
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}
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}
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if(EC32(section_hdr[i].Characteristics) & 0x20000000)
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cli_dbgmsg("Section's memory is executable\n");
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cli_dbgmsg("------------------------------------\n");
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if(EC32(section_hdr[i].PointerToRawData) + EC32(section_hdr[i].SizeOfRawData) > sb.st_size) {
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cli_dbgmsg("Possibly broken PE file - Section %d out of file (Offset@ %d, Rsize %d, Total filesize %d)\n", i, EC32(section_hdr[i].PointerToRawData), EC32(section_hdr[i].SizeOfRawData), sb.st_size);
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free(section_hdr);
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if(DETECT_BROKEN) {
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if(virname)
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*virname = "Broken.Executable";
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return CL_VIRUS;
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}
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return CL_CLEAN;
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}
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if(!i) {
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min = EC32(section_hdr[i].VirtualAddress);
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max = EC32(section_hdr[i].VirtualAddress) + EC32(section_hdr[i].SizeOfRawData);
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} else {
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if(EC32(section_hdr[i].VirtualAddress) < min)
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min = EC32(section_hdr[i].VirtualAddress);
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if(EC32(section_hdr[i].VirtualAddress) + EC32(section_hdr[i].SizeOfRawData) > max)
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max = EC32(section_hdr[i].VirtualAddress) + EC32(section_hdr[i].SizeOfRawData);
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}
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}
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if((ep = cli_rawaddr(EC32(optional_hdr.AddressOfEntryPoint), section_hdr, nsections)) == -1) {
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cli_dbgmsg("Possibly broken PE file\n");
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free(section_hdr);
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if(DETECT_BROKEN) {
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if(virname)
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*virname = "Broken.Executable";
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return CL_VIRUS;
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}
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return CL_CLEAN;
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}
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cli_dbgmsg("EntryPoint offset: 0x%x (%d)\n", ep, ep);
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/* UPX support */
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/* try to find the first section with physical size == 0 */
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found = 0;
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for(i = 0; i < nsections - 1; i++) {
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if(!section_hdr[i].SizeOfRawData && section_hdr[i].VirtualSize && section_hdr[i+1].SizeOfRawData && section_hdr[i+1].VirtualSize) {
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found = 1;
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cli_dbgmsg("UPX: empty section found - assuming UPX compression\n");
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break;
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}
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}
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if(found) {
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strncpy(sname, section_hdr[i].Name, 8);
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sname[8] = 0;
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cli_dbgmsg("UPX: Section %d name: %s\n", i, sname);
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strncpy(sname, section_hdr[i + 1].Name, 8);
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sname[8] = 0;
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cli_dbgmsg("UPX: Section %d name: %s\n", i + 1, sname);
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if(strncmp(section_hdr[i].Name, "UPX0", 4) || strncmp(section_hdr[i + 1].Name, "UPX1", 4))
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cli_dbgmsg("UPX: Possibly hacked UPX section headers\n");
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/* we assume (i + 1) is UPX1 */
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ssize = EC32(section_hdr[i + 1].SizeOfRawData);
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dsize = EC32(section_hdr[i].VirtualSize) + EC32(section_hdr[i + 1].VirtualSize);
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if(limits && limits->maxfilesize && (ssize > limits->maxfilesize || dsize > limits->maxfilesize)) {
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cli_dbgmsg("UPX: Sizes exceeded (ssize: %d, dsize: %d, max: %lu)\n", ssize, dsize , limits->maxfilesize);
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free(section_hdr);
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return CL_CLEAN;
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}
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if(ssize <= 0x19 || dsize <= ssize) { /* FIXME: What are reasonable values? */
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cli_dbgmsg("UPX: Size mismatch (ssize: %d, dsize: %d)\n", ssize, dsize);
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free(section_hdr);
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return CL_CLEAN;
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}
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/* FIXME: use file operations in case of big files */
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if((src = (char *) cli_malloc(ssize)) == NULL) {
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free(section_hdr);
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return CL_EMEM;
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}
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if((dest = (char *) cli_calloc(dsize, sizeof(char))) == NULL) {
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free(section_hdr);
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free(src);
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return CL_EMEM;
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}
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|
|
lseek(desc, EC32(section_hdr[i + 1].PointerToRawData), SEEK_SET);
|
|
if(read(desc, src, ssize) != ssize) {
|
|
cli_dbgmsg("Can't read raw data of section %d\n", i);
|
|
free(section_hdr);
|
|
free(src);
|
|
free(dest);
|
|
return CL_EIO;
|
|
}
|
|
|
|
/* try to detect UPX code */
|
|
|
|
if(lseek(desc, ep, SEEK_SET) == -1) {
|
|
cli_dbgmsg("lseek() failed\n");
|
|
free(section_hdr);
|
|
free(src);
|
|
free(dest);
|
|
return CL_EIO;
|
|
}
|
|
|
|
if(read(desc, buff, 126) != 126) { /* i.e. 0x69 + 13 + 8 */
|
|
cli_dbgmsg("UPX: Can't read 126 bytes at 0x%x (%d)\n", ep, ep);
|
|
free(section_hdr);
|
|
free(src);
|
|
free(dest);
|
|
return CL_EIO;
|
|
} else {
|
|
if(cli_memstr(UPX_NRV2B, 24, buff + 0x69, 13) || cli_memstr(UPX_NRV2B, 24, buff + 0x69 + 8, 13)) {
|
|
cli_dbgmsg("UPX: Looks like a NRV2B decompression routine\n");
|
|
upxfn = upx_inflate2b;
|
|
} else if(cli_memstr(UPX_NRV2D, 24, buff + 0x69, 13) || cli_memstr(UPX_NRV2D, 24, buff + 0x69 + 8, 13)) {
|
|
cli_dbgmsg("UPX: Looks like a NRV2D decompression routine\n");
|
|
upxfn = upx_inflate2d;
|
|
} else if(cli_memstr(UPX_NRV2E, 24, buff + 0x69, 13) || cli_memstr(UPX_NRV2E, 24, buff + 0x69 + 8, 13)) {
|
|
cli_dbgmsg("UPX: Looks like a NRV2E decompression routine\n");
|
|
upxfn = upx_inflate2e;
|
|
}
|
|
}
|
|
|
|
if(upxfn) {
|
|
int skew = cli_readint32(buff + 2) - EC32(optional_hdr.ImageBase) - EC32(section_hdr[i+1].VirtualAddress);
|
|
|
|
if(buff[1] != '\xbe' || skew <= 0 || skew > 0xfff ) { /* FIXME: legit skews?? */
|
|
skew = 0;
|
|
if(!upxfn(src, ssize, dest, dsize))
|
|
upx_success = 1;
|
|
|
|
} else {
|
|
cli_dbgmsg("UPX: UPX1 seems skewed by %d bytes\n", skew);
|
|
if(!upxfn(src + skew, ssize - skew, dest, dsize) || !upxfn(src, ssize, dest, dsize))
|
|
upx_success = 1;
|
|
}
|
|
|
|
if(upx_success)
|
|
cli_dbgmsg("UPX: Successfully decompressed\n");
|
|
else
|
|
cli_dbgmsg("UPX: Prefered decompressor failed\n");
|
|
}
|
|
|
|
if(!upx_success && upxfn != upx_inflate2b) {
|
|
if(upx_inflate2b(src, ssize, dest, dsize) && upx_inflate2b(src + 0x15, ssize - 0x15, dest, dsize) ) {
|
|
cli_dbgmsg("UPX: NRV2B decompressor failed\n");
|
|
} else {
|
|
upx_success = 1;
|
|
cli_dbgmsg("UPX: Successfully decompressed with NRV2B\n");
|
|
}
|
|
}
|
|
|
|
if(!upx_success && upxfn != upx_inflate2d) {
|
|
if(upx_inflate2d(src, ssize, dest, dsize) && upx_inflate2d(src+0x15, ssize-0x15, dest, dsize) ) {
|
|
cli_dbgmsg("UPX: NRV2D decompressor failed\n");
|
|
} else {
|
|
upx_success = 1;
|
|
cli_dbgmsg("UPX: Successfully decompressed with NRV2D\n");
|
|
}
|
|
}
|
|
|
|
if(!upx_success && upxfn != upx_inflate2e) {
|
|
if(upx_inflate2e(src, ssize, dest, dsize) && upx_inflate2e(src + 0x15, ssize - 0x15, dest, dsize) ) {
|
|
cli_dbgmsg("UPX: NRV2E decompressor failed\n");
|
|
} else {
|
|
upx_success = 1;
|
|
cli_dbgmsg("UPX: Successfully decompressed with NRV2E\n");
|
|
}
|
|
}
|
|
|
|
if(!upx_success) {
|
|
cli_dbgmsg("UPX: All decompressors failed\n");
|
|
} else {
|
|
int ndesc;
|
|
|
|
if(cli_leavetemps_flag) {
|
|
tempfile = cli_gentemp(NULL);
|
|
if((ndesc = open(tempfile, O_WRONLY|O_CREAT|O_TRUNC, S_IRWXU)) < 0) {
|
|
cli_dbgmsg("UPX: Can't create file %s\n", tempfile);
|
|
free(tempfile);
|
|
free(section_hdr);
|
|
free(src);
|
|
free(dest);
|
|
return CL_EIO;
|
|
}
|
|
|
|
if(write(ndesc, dest, dsize) != dsize) {
|
|
cli_dbgmsg("Can't write %d bytes\n", dsize);
|
|
free(tempfile);
|
|
free(section_hdr);
|
|
free(src);
|
|
free(dest);
|
|
return CL_EIO;
|
|
}
|
|
|
|
close(ndesc);
|
|
cli_dbgmsg("UPX: Decompressed data saved in %s\n", tempfile);
|
|
free(tempfile);
|
|
}
|
|
|
|
if(cl_scanbuff(dest, dsize, virname, root) == CL_VIRUS) {
|
|
free(section_hdr);
|
|
free(src);
|
|
free(dest);
|
|
return CL_VIRUS;
|
|
}
|
|
}
|
|
|
|
free(src);
|
|
free(dest);
|
|
}
|
|
|
|
/* Petite */
|
|
|
|
found = 2;
|
|
|
|
lseek(desc, ep, SEEK_SET);
|
|
if(read(desc, buff, 200) != 200) {
|
|
free(section_hdr);
|
|
return CL_EIO;
|
|
}
|
|
|
|
if(buff[0] != '\xb8' || cli_readint32(buff + 1) != EC32(section_hdr[nsections - 1].VirtualAddress) + EC32(optional_hdr.ImageBase)) {
|
|
if(buff[0] != '\xb8' || cli_readint32(buff + 1) != EC32(section_hdr[nsections - 2].VirtualAddress) + EC32(optional_hdr.ImageBase))
|
|
found = 0;
|
|
else
|
|
found = 1;
|
|
}
|
|
|
|
if(found) {
|
|
cli_dbgmsg("Petite: v2.%d compression detected\n", found);
|
|
|
|
if(cli_readint32(buff + 0x80) == 0x163c988d) {
|
|
cli_dbgmsg("Petite: level zero compression is not supported yet\n");
|
|
} else {
|
|
dsize = max - min;
|
|
|
|
if(limits && limits->maxfilesize && dsize > limits->maxfilesize) {
|
|
cli_dbgmsg("Petite: Size exceeded (dsize: %d, max: %lu)\n", dsize, limits->maxfilesize);
|
|
free(section_hdr);
|
|
return CL_CLEAN;
|
|
}
|
|
|
|
if((dest = (char *) cli_calloc(dsize, sizeof(char))) == NULL) {
|
|
cli_dbgmsg("Petite: Can't allocate %d bytes\n", dsize);
|
|
free(section_hdr);
|
|
return CL_EMEM;
|
|
}
|
|
|
|
for(i = 0 ; i < nsections; i++) {
|
|
lseek(desc, cli_rawaddr(EC32(section_hdr[i].VirtualAddress), section_hdr, nsections), SEEK_SET);
|
|
read(desc, dest + EC32(section_hdr[i].VirtualAddress) - min, EC32(section_hdr[i].SizeOfRawData));
|
|
}
|
|
|
|
tempfile = cli_gentemp(NULL);
|
|
if((ndesc = open(tempfile, O_RDWR|O_CREAT|O_TRUNC, S_IRWXU)) < 0) {
|
|
cli_dbgmsg("Petite: Can't create file %s\n", tempfile);
|
|
free(tempfile);
|
|
free(section_hdr);
|
|
free(dest);
|
|
return CL_EIO;
|
|
}
|
|
|
|
switch(petite_inflate2x_1to9(dest, min, max - min, section_hdr,
|
|
nsections, EC32(optional_hdr.ImageBase), ep, ndesc,
|
|
found, EC32(optional_hdr.DataDirectory[2].VirtualAddress),
|
|
EC32(optional_hdr.DataDirectory[2].Size))) {
|
|
case 1:
|
|
cli_dbgmsg("Petite: Unpacked and rebuilt executable saved in %s\n", tempfile);
|
|
break;
|
|
|
|
case 0:
|
|
cli_dbgmsg("Petite: Unpacked data saved in %s\n", tempfile);
|
|
break;
|
|
|
|
default:
|
|
cli_dbgmsg("Petite: Unpacking failed\n");
|
|
}
|
|
|
|
free(dest);
|
|
fsync(ndesc);
|
|
lseek(ndesc, 0, SEEK_SET);
|
|
|
|
if(cli_magic_scandesc(ndesc, virname, scanned, root, limits, options, arec, mrec) == CL_VIRUS) {
|
|
free(section_hdr);
|
|
close(ndesc);
|
|
if(!cli_leavetemps_flag) {
|
|
unlink(tempfile);
|
|
free(tempfile);
|
|
} else {
|
|
free(tempfile);
|
|
}
|
|
return CL_VIRUS;
|
|
}
|
|
|
|
close(ndesc);
|
|
|
|
if(!cli_leavetemps_flag) {
|
|
unlink(tempfile);
|
|
free(tempfile);
|
|
} else {
|
|
free(tempfile);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* to be continued ... */
|
|
|
|
free(section_hdr);
|
|
return CL_CLEAN;
|
|
}
|
|
|