Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 cb8b96828d93b17b…

MALICIOUS

RTF / .DOC

25.8 KB First seen: 2022-12-15
MD5: 79fde8c0e4847ff6d6cfb98d82ca5979 SHA-1: e824937e557b53213a4d5e719c8da883b35c111f SHA-256: cb8b96828d93b17bba93f1c8d6a270fec9e03e9233c513a8bfd50941bb8a21a7
140 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object with a split Equation Editor ProgID, indicating an attempt to exploit the Microsoft Equation Editor vulnerability. The presence of \objupdate further suggests that the object is designed to be activated automatically. The document body contains a lure instructing the user to 'Enable editing', a common tactic to bypass macro security and trigger the exploit. No scripts were extracted, but the heuristics strongly suggest a client-side exploit targeting the Equation Editor.

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_off00004fac.bin
710070aa1f255428650597091037cbf11e6d38b9d5f54448625a6fe1eacfbaad
rtf-objdata-decoded RTF \objdata at offset 0x4FAC 1693 bytes