Potential Defense Evasion Via Right-to-Left Override

Detects the presence of the "u202+E" character, which causes a terminal, browser, or operating system to render text in a right-to-left sequence. This is used as an obfuscation and masquerading techniques.

Sigma rule (View on GitHub)

 1title: Potential Defense Evasion Via Right-to-Left Override
 2id: ad691d92-15f2-4181-9aa4-723c74f9ddc3
 3related:
 4    - id: e0552b19-5a83-4222-b141-b36184bb8d79
 5      type: derived
 6    - id: 584bca0f-3608-4402-80fd-4075ff6072e3
 7      type: derived
 8status: test
 9description: |
10    Detects the presence of the "u202+E" character, which causes a terminal, browser, or operating system to render text in a right-to-left sequence.
11    This is used as an obfuscation and masquerading techniques.    
12references:
13    - https://redcanary.com/blog/right-to-left-override/
14    - https://www.malwarebytes.com/blog/news/2014/01/the-rtlo-method
15    - https://unicode-explorer.com/c/202E
16author: Micah Babinski, @micahbabinski
17date: 2023-02-15
18tags:
19    - attack.defense-evasion
20    - attack.t1036.002
21logsource:
22    category: process_creation
23    product: windows
24detection:
25    selection:
26        CommandLine|contains: "\u202e"
27    condition: selection
28falsepositives:
29    - Commandlines that contains scriptures such as arabic or hebrew might make use of this character
30level: high

References

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