Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 8a2fa9c6b4cb7893…

MALICIOUS

RTF / .DOC

27.1 KB First seen: 2022-11-09
MD5: 22c21f0a223c50343d8ebe4c9bc6d1a8 SHA-1: 0ab738735c4589141679dd79b714b1d9b0755e13 SHA-256: 8a2fa9c6b4cb789374f001ce78ec0d2891716874830487d47005a66ac7069376
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1059 Command and Scripting Interpreter T1559 Component Object Model Hijacking

The sample is an RTF document that contains an embedded OLE object with an Equation Editor ProgID, indicating an attempt to exploit CVE-2017-11882. The \objupdate directive forces OLE activation, and the SE_ENABLE_LURE heuristic suggests the document prompts the user to enable content. This combination strongly suggests the document is a lure to trigger an exploit that likely downloads and executes a second-stage 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_off0000567e.bin
e0dfdaa42b51952186dda66370266ca33e91c3fee464fc6937a7c682afa7d486
rtf-objdata-decoded RTF \objdata at offset 0x567E 1596 bytes