Suspicious Activity in Shell Commands

Detects suspicious shell commands used in various exploit codes (see references)

Sigma rule (View on GitHub)

 1title: Suspicious Activity in Shell Commands
 2id: 2aa1440c-9ae9-4d92-84a7-a9e5f5e31695
 3status: test
 4description: Detects suspicious shell commands used in various exploit codes (see references)
 5references:
 6    - https://web.archive.org/web/20170319121015/http://www.threatgeek.com/2017/03/widespread-exploitation-attempts-using-cve-2017-5638.html
 7    - https://github.com/rapid7/metasploit-framework/blob/eb6535009f5fdafa954525687f09294918b5398d/modules/exploits/multi/http/struts_code_exec_exception_delegator.rb
 8    - http://pastebin.com/FtygZ1cg
 9    - https://artkond.com/2017/03/23/pivoting-guide/
10author: Florian Roth (Nextron Systems)
11date: 2017-08-21
12modified: 2021-11-27
13tags:
14    - attack.execution
15    - attack.t1059.004
16logsource:
17    product: linux
18detection:
19    keywords:
20        # Generic suspicious commands
21        - 'wget * - http* | perl'
22        - 'wget * - http* | sh'
23        - 'wget * - http* | bash'
24        - 'python -m SimpleHTTPServer'
25        - '-m http.server'      # Python 3
26        - 'import pty; pty.spawn*'
27        - 'socat exec:*'
28        - 'socat -O /tmp/*'
29        - 'socat tcp-connect*'
30        - '*echo binary >>*'
31        # Malware
32        - '*wget *; chmod +x*'
33        - '*wget *; chmod 777 *'
34        - '*cd /tmp || cd /var/run || cd /mnt*'
35        # Apache Struts in-the-wild exploit codes
36        - '*stop;service iptables stop;*'
37        - '*stop;SuSEfirewall2 stop;*'
38        - 'chmod 777 2020*'
39        - '*>>/etc/rc.local'
40        # Metasploit framework exploit codes
41        - '*base64 -d /tmp/*'
42        - '* | base64 -d *'
43        - '*/chmod u+s *'
44        - '*chmod +s /tmp/*'
45        - '*chmod u+s /tmp/*'
46        - '* /tmp/haxhax*'
47        - '* /tmp/ns_sploit*'
48        - 'nc -l -p *'
49        - 'cp /bin/ksh *'
50        - 'cp /bin/sh *'
51        - '* /tmp/*.b64 *'
52        - '*/tmp/ysocereal.jar*'
53        - '*/tmp/x *'
54        - '*; chmod +x /tmp/*'
55        - '*;chmod +x /tmp/*'
56    condition: keywords
57falsepositives:
58    - Unknown
59level: high

References

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