Suspicious Reverse Shell Command Line

Title: Suspicious Reverse Shell Command Line
Status: test
Description:Detects suspicious shell commands or program code that may be executed or used in command line to establish a reverse shell
References:
  -https://alamot.github.io/reverse_shells/
Author: Florian Roth (Nextron Systems)
Date: 2019-04-02
modified:2021-11-27
Tags:

• -'attack.execution'
• -'attack.t1059.004'

Logsource:

• product: linux

Detection:
  keywords:
    - 'BEGIN {s = "/inet/tcp/0/'
    - 'bash -i >& /dev/tcp/'
    - 'bash -i >& /dev/udp/'
    - 'sh -i >$ /dev/udp/'
    - 'sh -i >$ /dev/tcp/'
    - '&& while read line 0<&5; do'
    - '/bin/bash -c exec 5<>/dev/tcp/'
    - '/bin/bash -c exec 5<>/dev/udp/'
    - 'nc -e /bin/sh '
    - '/bin/sh | nc'
    - 'rm -f backpipe; mknod /tmp/backpipe p && nc '
    - ';socket(S,PF_INET,SOCK_STREAM,getprotobyname("tcp"));if(connect(S,sockaddr_in($p,inet_aton($i))))'
    - ';STDIN->fdopen($c,r);$~->fdopen($c,w);system$_ while<>;'
    - '/bin/sh -i <&3 >&3 2>&3'
    - 'uname -a; w; id; /bin/bash -i'
    - '$sendbyte = ([text.encoding]::ASCII).GetBytes($sendback2); $stream.Write($sendbyte,0,$sendbyte.Length); $stream.Flush()};'
    - ';os.dup2(s.fileno(),0);os.dup2(s.fileno(),1);os.dup2(s.fileno(),2);os.putenv('HISTFILE','/dev/null');'
    - '.to_i;exec sprintf("/bin/sh -i <&%d >&%d 2>&%d",f,f,f)'
    - ';while(cmd=c.gets);IO.popen(cmd,"r"){|io|c.print'
    - 'socat exec:'bash -li',pty,stderr,setsid,sigint,sane tcp:'
    - 'rm -f /tmp/p; mknod /tmp/p p &&'
    - ' | /bin/bash | telnet '
    - ',echo=0,raw tcp-listen:'
    - 'nc -lvvp '
    - 'xterm -display 1'
  condition:keywords
Falsepositives:
  -Unknown
Level: high