Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 bdd586a33bfd9b73…

MALICIOUS

RTF / .DOC

99.1 KB First seen: 2023-09-29
MD5: 0110034c3a13e96317d374e3eceddf44 SHA-1: 67f631c83a5edb57cc1719dded70585b7b6392bc SHA-256: bdd586a33bfd9b732e20e49628e827a510a322f3a9df7edee7d8e631c510611a
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution: Malicious Link T1059.005 PowerShell

The sample is an RTF document containing OLE object data and specifically targets the Equation Editor vulnerability (RTF_EQUATION_EDITOR). The presence of \objupdate suggests an attempt to automatically activate the embedded object, which is a common lure to exploit the vulnerability. The document body contains a generic lure instructing the user to 'Enable editing', aligning with the SE_ENABLE_LURE heuristic.

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_off00006aa2.bin
fb6ea903bab2273eb20eb06a951eb07df5fec533e39ad9217ca34bb5d1837d3d
rtf-objdata-decoded RTF \objdata at offset 0x6AA2 1584 bytes