75 lines
2.8 KiB
YAML
75 lines
2.8 KiB
YAML
title: Antivirus Web Shell Detection
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id: fdf135a2-9241-4f96-a114-bb404948f736
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description: Detects a highly relevant Antivirus alert that reports a web shell. It's highly recommended to tune this rule to the specific strings used by your anti virus solution by downloading a big webshell repo from e.g. github and checking the matches.
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status: experimental
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date: 2018/09/09
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modified: 2021/05/08
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author: Florian Roth, Arnim Rupp
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references:
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- https://www.nextron-systems.com/2021/03/25/antivirus-event-analysis-cheat-sheet-v1-8/
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- https://github.com/tennc/webshell
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- https://www.virustotal.com/gui/file/bd1d52289203866645e556e2766a21d2275877fbafa056a76fe0cf884b7f8819/detection
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- https://www.virustotal.com/gui/file/308487ed28a3d9abc1fec7ebc812d4b5c07ab025037535421f64c60d3887a3e8/detection
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- https://www.virustotal.com/gui/file/7d3cb8a8ff28f82b07f382789247329ad2d7782a72dde9867941f13266310c80/detection
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- https://www.virustotal.com/gui/file/e841675a4b82250c75273ebf0861245f80c6a1c3d5803c2d995d9d3b18d5c4b5/detection
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- https://www.virustotal.com/gui/file/a80042c61a0372eaa0c2c1e831adf0d13ef09feaf71d1d20b216156269045801/detection
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- https://www.virustotal.com/gui/file/b219f7d3c26f8bad7e175934cd5eda4ddb5e3983503e94ff07d39c0666821b7e/detection
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- https://www.virustotal.com/gui/file/b8702acf32fd651af9f809ed42d15135f842788cd98d81a8e1b154ee2a2b76a2/detection
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tags:
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- attack.persistence
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- attack.t1505.003
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logsource:
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product: antivirus
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detection:
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selection:
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- Signature|startswith:
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- 'PHP/'
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- 'JSP/'
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- 'ASP/'
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- 'Perl/'
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- 'PHP.'
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- 'JSP.'
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- 'ASP.'
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- 'Perl.'
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- 'VBS/Uxor' # looking for 'VBS/' would also find downloaders and droppers meant for desktops
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- 'IIS/BackDoor'
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- 'JAVA/Backdoor'
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- 'Troj/ASP'
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- 'Troj/PHP'
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- 'Troj/JSP'
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- Signature|contains:
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- 'Webshell'
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- 'Chopper'
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- 'SinoChoper'
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- 'ASPXSpy'
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- 'Aspdoor'
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- 'filebrowser'
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- 'PHP_'
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- 'JSP_'
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- 'ASP_' # looking for 'VBS_' would also find downloaders and droppers meant for desktops
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- 'PHP:'
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- 'JSP:'
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- 'ASP:'
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- 'Perl:'
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- 'PHPShell'
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- 'Trojan.PHP'
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- 'Trojan.ASP'
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- 'Trojan.JSP'
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- 'Trojan.VBS'
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- 'PHP?Agent'
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- 'ASP?Agent'
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- 'JSP?Agent'
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- 'VBS?Agent'
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- 'Backdoor?PHP'
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- 'Backdoor?JSP'
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- 'Backdoor?ASP'
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- 'Backdoor?VBS'
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- 'Backdoor?Java'
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condition: selection
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fields:
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- FileName
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- User
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falsepositives:
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- Unlikely
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level: critical
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