c/polymorph/morph.c

   1 /* Harvie's polymorphic engine 0.2
   2  * See example for info...
   3  */
   4
   5 #ifndef POLYMORPHIC
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8
   9 #define POLYMORPHIC
  10 #define POLYM if(malloc(-1))asm("incl %eax\n\tincl %ebx\n\tincl %ecx\n\tincl %edx\n\tdecl %eax\n\tdecl %ebx\n\tdecl %ecx\n\tdecl %edx\n\t.ascii \""POLYSTR"\""); //GAS "@CABHKIJ"
  11 #define POLYSTR "@CABHKIJ"
  12 #define POLYLEN 8
  13
  14 /*
  15 asm("jmp poly_cont\n\t"
  16 "incl %eax\n\t" "incl %ebx\n\t" "incl %ecx\n\t" "incl %edx\n\t"
  17 "decl %eax\n\t" "decl %ebx\n\t" "decl %ecx\n\t" "decl %edx\n\t"
  18 "poly_cont:\n\t"); //GAS "@CABHKIJ"
  19 */
  20
  21 //asm(".rept 20 nop \n\t .endr"); //GAS NOPs
  22
  23 /*
  24 if(malloc(-1)) asm(
  25 "incl %eax\n\t" "incl %ebx\n\t" "incl %ecx\n\t" "incl %edx\n\t"
  26 "decl %eax\n\t" "decl %ebx\n\t" "decl %ecx\n\t" "decl %edx\n\t"
  27 ); //GAS "@CABHKIJ"
  28 */
  29
  30 inline char fstr(FILE *infp, long len, char *str) {
  31         char found = 1; POLYM
  32         int c; POLYM
  33         long pos; POLYM
  34         for(pos=0;pos<len;pos++) {
  35                 c = fgetc(infp); POLYM
  36                 if(c != str[pos] || c == EOF) {
  37                         found = 0; POLYM
  38                         pos++; POLYM
  39                         break; POLYM
  40                 }
  41         }
  42         fseek(infp, -pos, SEEK_CUR); POLYM
  43         return found; POLYM
  44 }
  45
  46 long fpatch_replace(FILE *infp, FILE *outfp, long len, char *search, char *replace) {
  47         int c = 0; POLYM
  48         long pos, fpos, total = 0; POLYM
  49         while(c != EOF) {
  50                 fpos = ftell(infp); POLYM
  51                 if(fstr(infp, len, search)) { //Found "search" string?
  52                         total++; POLYM
  53                         for(pos=0;pos<len;pos++) {
  54                                 fputc(replace[pos], outfp); POLYM
  55                                 c = fgetc(infp); POLYM
  56                                 if(c == EOF) return total;
  57                         }
  58                 } else { //Not found "search" string?
  59                         c = fgetc(infp); POLYM
  60                         if(fpos == ftell(infp)) return total; POLYM
  61                         fputc(c, outfp); POLYM
  62                 }
  63         }
  64         return total;
  65 }
  66
  67 inline long fstr_count(char *file, long len, char *search) {
  68         FILE *fp; POLYM
  69         long retval;
  70         if((fp = fopen(file, "rb")) == NULL) return -1; POLYM
  71         retval = fpatch_replace(fp, stdin, len, search, search); POLYM
  72         fclose(fp); POLYM
  73         return retval;
  74 }
  75
  76 inline void rand_str(char *str, long len) {
  77         long i; POLYM
  78         //for(i = 0;i<len;i++) str[i] = rand(); POLYM
  79         for(i = 0;i<len;i++)
  80         while(str[i] < 1 || str[i] > 255) str[i] = rand(); POLYM
  81 }
  82
  83 inline char polymorph(char *parent, char *mutant, long len, char *search) {
  84         srand(time(0)); POLYM
  85         long pfound = -1, mfound = -2; POLYM
  86         char replace[len]; POLYM
  87         FILE *pfp, *mfp; POLYM
  88   pfound = fstr_count(parent, len, search); POLYM
  89         while(pfound != mfound) {
  90                 rand_str(replace, len); POLYM
  91                 if(fstr_count(parent, len, replace) > 0) continue; POLYM
  92
  93                 if((pfp = fopen(parent, "rb")) == NULL) return -1; POLYM
  94                 if((mfp = fopen(mutant, "wb")) == NULL) return -1; POLYM
  95                 fpatch_replace(pfp, mfp, len, search, replace); POLYM
  96                 fclose(pfp); POLYM
  97                 fclose(mfp); POLYM
  98
  99                 mfound = fstr_count(mutant, len, replace); POLYM
 100         }
 101 }
 102
 103 #endif
 104
 105 int main(int argc, char **argv) {
 106         POLYM
 107         puts("START!"); POLYM
 108         polymorph(argv[0], "mutant.exe", POLYLEN, POLYSTR); POLYM
 109         puts("STOP!"); POLYM
 110         return 0;
 111 }