Potential Defense Evasion Via Right-to-Left Override

 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
16    - https://tria.ge/241015-l98snsyeje/behavioral2
17author: Micah Babinski, @micahbabinski, Swachchhanda Shrawan Poudel (Nextron Systems)
18date: 2023-02-15
19modified: 2025-02-06
20tags:
21    - attack.defense-evasion
22    - attack.t1036.002
23logsource:
24    category: process_creation
25    product: windows
26detection:
27    selection:
28        CommandLine|contains:
29            - '\u202e'  # Unicode RTLO character
30            - '[U+202E]'
31    condition: selection
32falsepositives:
33    - Commandlines that contains scriptures such as arabic or hebrew might make use of this character
34level: high

References

• Right-to-Left Override: Detecting Attacks With EDR Data

  

  Our Security Operations team loves to share insights on TTPs when we see them in the wild. Today an oldie but a goodie: right-to-left override attacks.

  
  Read More

• The RTLO method | Malwarebytes Labs

  

  RTLO can be used to spoof fake extensions. Learn how malware writers are using this old trick to spread malware.

  
  Read More

• U+202E RIGHT-TO-LEFT OVERRIDE - Unicode Explorer

  U+202E RIGHT-TO-LEFT OVERRIDE, copy and paste, unicode character symbol info, commonly abbreviated RLO

  
  Read More

• ae8d252986c616884c10ab5082088cc9e413ddf5f9a0e292a1f2c5c0764c74e7 | Triage

  Check this report malware sample ae8d252986c616884c10ab5082088cc9e413ddf5f9a0e292a1f2c5c0764c74e7, with a score of 1 out of 10.

  
  Read More

Related rules

• MMC Executing Files with Reversed Extensions Using RTLO Abuse
• Potential File Extension Spoofing Using Right-to-Left Override
• MMC Loading Script Engines DLLs
• Potentially Suspicious Child Processes Spawned by ConHost
• Scheduled Task Creation Masquerading as System Processes