Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 c789a9d5ffd38dc8…

MALICIOUS

RTF / .DOC

24.2 KB First seen: 2022-11-15
MD5: 406a707b7492798c50beb5be63706c0e SHA-1: 0bcc99bf60512df807dad684747516419834df8d SHA-256: c789a9d5ffd38dc8bb128b4b86b40e71277d32c0ea593f17d105acbf34aef235
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1059 Command and Scripting Interpreter

The sample is an RTF document that contains an embedded OLE object with a specific ProgID associated with the Equation Editor. The ".objupdate" directive indicates that the embedded object will be activated upon opening, triggering an exploit. The document body contains a lure instructing the user to 'Enable editing', which is a common tactic to bypass security warnings and facilitate the exploitation of vulnerabilities like CVE-2017-11882.

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_off0000470f.bin
f11bbaf652e69b05502fb27a0a7411fab55bca122015742aa8dfaf9be387e988
rtf-objdata-decoded RTF \objdata at offset 0x470F 1422 bytes