C Troubles with comparison between two binary data - c

Question

I am writing a program that get a path for a folder with two pictures files and a path for a file that containing binary data that simulator virus. and the purpose of this final project is to scan the files in the folder and say if one hold the virus. I succeeded with opening all the files but my comparison does not working. please someone help me fix this code because I am clueless why this is happening and this is my final project to get a grade on. The problem is in the line when I use memcmp function.
#include <stdio.h>
#include "dirent.h"
#include <string.h>
int print_menu(char *argv[]); // this is a function that print to the user the menu and it's not appears in this question.
void long_scan(char *info[]);
#define STR_LEN 100
int main(int argc, char *argv[])
{
int option = 0;
if (argc == 3)
{
option = print_menu(argv);
if (option == 0)
{
long_scan(argv);
}
}
else
{
printf("The program didn't got the number of paramter's that she expect to get\n");
}
getchar();
return 0;
}
void long_scan(char *info[])
{
DIR *file = 0; // the folder
FILE *file_to_check = 0; // the files to check in this case the pictures
FILE *virus; // the virus file
struct dirent *files = 0;
char temp[STR_LEN] = { 0 }; // using to play with the strings to open the files
int len = 0, result = 0, c = 0, virus_len = 0, i = 0;
char file_p[STR_LEN] = { 0 };
char virus_path[STR_LEN] = { 0 };
strcpy(file_p, info[1]); // the path of the folder
strcpy(virus_path, info[2]); // the path to the virus
file = opendir(file_p); // opening the folder
strcat(file_p, "\\\\"); add "\\" to the path so I can get the files in the folder later on
virus = fopen(virus_path, "rb"); // opening the virus
fseek(virus, 0, SEEK_END);
virus_len = ftell(virus); // get the virus len = 494
fseek(virus, 0, SEEK_SET);
char* virus_holder = (char *)malloc(sizeof(char) * virus_len); // create variable for the virus
fread(virus_holder, sizeof(char), virus_len, virus); // get the virus to the variable (his len is 61 dont know why)
if (file == NULL) // check if the file exist
{
printf("Error. file does not exists\n");
exit(0);
}
while ((files = readdir(file)) != NULL) // get one file every time
{
if (strcmp(files->d_name, "..") && strcmp(files->d_name, "."))
{
strcpy(temp, file_p); // copy the original path for later
strcat(file_p, files->d_name); // get the path to the file
file_to_check = fopen(file_p, "rb"); // open the file (picture)
fseek(file_to_check, 0, SEEK_END);
len = ftell(file_to_check); // get the file len
fseek(file_to_check, 0, SEEK_SET);
char* buffer = (char *)malloc(sizeof(char) * len); // create buffer to hold the file binary data
fread(buffer, sizeof(char), len, file_to_check);
fclose(file_to_check);
/*******/
result = memcmp(virus_holder, buffer, virus_len); // here the problem his. for some resone th compare does not work for me. and one of the file his holding the virus for 100%
/*******/
if (result == 0)
{
printf("%s is holding the virus\n", files->d_name);
}
strcpy(file_p, temp); // get the original path
free(buffer);
}
}
free(virus_holder);
}