Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 64b6bc16d04589ed…

MALICIOUS

RTF / .DOC

36.5 KB First seen: 2023-02-22
MD5: f256783e3b6fdf6ddfc03782e43f66df SHA-1: cca8190f8146840e318fc15590f551d7f971883f SHA-256: 64b6bc16d04589ed51bdd1e5197034dfb1b829d66d6f73529009f7b318e47cad
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution: Malicious Link T1059.005 Command and Scripting Interpreter: Visual Basic

The sample is an RTF document containing an embedded OLE object, specifically targeting the Equation Editor vulnerability. The 'SE_ENABLE_LURE' heuristic indicates the document prompts the user to enable editing, a common tactic to bypass security measures. The presence of 'RTF_OBJUPDATE' suggests the embedded object is designed to be activated automatically upon opening, likely to trigger the Equation Editor exploit and download a secondary payload.

Heuristics 4

  • Split hex Equation Editor ProgID + OLE object critical RTF_EQUATION_EDITOR
    RTF embeds the Equation.3 ProgID as hex bytes near OLE object activation and splits the byte stream with whitespace or an ignorable RTF group. This is an Equation Editor OLE activation surface commonly used by CVE-2017-11882 / CVE-2018-0802 exploit documents.
  • \objupdate forces OLE activation high RTF_OBJUPDATE
    RTF contains \objupdate — forces automatic OLE object instantiation when the document is opened, bypassing user interaction. Almost exclusively seen in Equation Editor exploit documents.
  • OLE object data medium RTF_OBJDATA
    RTF contains 1 \objdata section(s) — embedded OLE objects
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off0000409f.bin
7d2cd1ab8583a7cfb4833716087ff707c5b5c5aefbc106395d8572a0ba5b39a9
rtf-objdata-decoded RTF \objdata at offset 0x409F 1536 bytes