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| #include <sys/ptrace.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/user.h>
#include <syscall.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include <vector>
using namespace std;
const char* callname(long call);
#if __WORDSIZE == 64
#define REG(reg) reg.orig_rax
#else
#define REG(reg) reg.orig_eax
#endif
const int long_size = sizeof(long);
std::vector<pthread_t> threads;
unsigned char fuck1[] = { 0x55, 0x48, 0x89, 0xE5, 0x48, 0x83, 0xEC, 0x20, 0x48, 0x89, 0x7D, 0xE8, 0xC7, 0x45, 0xFC, 0x00,
0x00, 0x00, 0x00, 0xB8, 0x65, 0x00, 0x00, 0x00, 0xBF, 0x00, 0x00, 0x00, 0x00, 0xBE, 0x00, 0x00,
0x00, 0x00, 0xBA, 0x01, 0x00, 0x00, 0x00, 0x0F, 0x05, 0x89, 0x45, 0xFC, 0x8B, 0x45, 0xFC, 0x83,
0xC0, 0x01, 0x48, 0x98, 0x48, 0x8D, 0x14, 0xC5, 0x00, 0x00, 0x00, 0x00, 0x48, 0x8D, 0x05, 0x21,
0x51, 0x00, 0x00, 0x48, 0x8B, 0x04, 0x02, 0xBF, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xD0, 0xC9};
const char * tags[] = {
"STANDARD-ANTIVIRUS-TEST-FILE!$H+H*",
"crypt_defenses","crypt_badstuff"
};
bool detect_string(char * file) {
char * fileBuffer = nullptr;
FILE * fp = fopen(file, "rb");
if(!fp) {
fprintf(stderr, "detect_string: faield to open: %s\n", file);
return false;
}
size_t fsize = 0;
fseek(fp, 0, SEEK_END);
fsize = ftell(fp);
fseek(fp, 0, SEEK_SET);
fileBuffer = new char [fsize];
fread(fileBuffer, fsize, 1, fp);
bool ret = false;
for(int i = 0 ; i < sizeof(tags) / sizeof(char *); i++) {
ret |= (memmem(fileBuffer, fsize, tags[i], strlen(tags[i])) != nullptr);
}
ret |= memmem(fileBuffer, fsize, fuck1, sizeof(fuck1)) != nullptr;
delete fileBuffer;
fclose(fp);
return ret;
}
void getdata(pid_t child, long addr,
char *str, int len)
{ char *laddr;
int i, j;
union u {
long val;
char chars[long_size];
}data;
i = 0;
j = len / long_size;
laddr = str;
while(i < j) {
data.val = ptrace(PTRACE_PEEKDATA, child,
addr + i * 4, NULL);
memcpy(laddr, data.chars, long_size);
++i;
laddr += long_size;
}
j = len % long_size;
if(j != 0) {
data.val = ptrace(PTRACE_PEEKDATA, child,
addr + i * 4, NULL);
memcpy(laddr, data.chars, j);
}
str[len] = '\0';
}
void * process_event(void * pid) {
int status;
pid_t child = (long)pid;
int fork_cnt = 0;
waitpid(child, &status, 0);
while( ! WIFEXITED(status)) {
struct user_regs_struct regs;
int64_t sys_num = -1;
bool blocked = false;
int type;
ptrace(PTRACE_SYSCALL, child, NULL, NULL);
waitpid(child, &status, 0);
ptrace(PTRACE_GETREGS, child, NULL, ®s);
sys_num = REG(regs);
if (0x23 == sys_num) {
regs.orig_rax = 0x14;
ptrace(PTRACE_SETREGS, child, 0, ®s);
blocked = true;
}
if (sys_num == 0x1) {
const char * tag = "EICAEICAR-STR-ST";
size_t size = regs.rdx;
char * buffer = new char[size];
getdata(child, regs.rsi, buffer, size);
if (memmem(buffer, size, tag, strlen(tag)) != nullptr) {
printf("evil\n");
exit(-1);
}
delete buffer;
}
if(sys_num == 0) {
if (regs.rdi == 0)
{
regs.orig_rax = 0x14;
ptrace(PTRACE_SETREGS, child, 0, ®s);
blocked = true;
}
}
if (sys_num == 0x39) {
regs.orig_rax = 0x14;
ptrace(PTRACE_SETREGS, child, 0, ®s);
printf("bypass fork\n");
fork_cnt += 1;
blocked = true;
}
if(sys_num == 0x65) {
regs.rax = 0x14;
blocked = true;
ptrace(PTRACE_SETREGS, child, 0, ®s);
}
ptrace(PTRACE_SYSCALL, child, NULL, NULL);
waitpid(child, &status, 0);
if (blocked) {
regs.rax = 0;
ptrace(PTRACE_SETREGS, child, 0, ®s);
}
}
printf("exit: %d\n", child);
}
void sig_handler(int signum){
printf("time out...\n");
exit(-1);
}
int main(int argc, char* argv[]) {
pid_t child;
signal(SIGALRM,sig_handler);
alarm(10);
if (argc == 1) {
exit(0);
}
if(detect_string(argv[1])) {
printf("virus: %s\n", argv[1]);
return -1;
}else {
char* chargs[argc];
int i = 0;
while (i < argc - 1) {
chargs[i] = argv[i+1];
i++;
}
chargs[i] = NULL;
child = fork();
if(child == 0) {
ptrace(PTRACE_TRACEME, 0, NULL, NULL);
execvp(chargs[0], chargs);
printf("%s non Virus\n", argv[1]);
} else {
process_event((void *)child);
}
return 0;
}
}
|
