Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 c4caba538d5d493b…

MALICIOUS

RTF / .DOC

3.4 KB First seen: 2022-03-22
MD5: 2f20c27b43267698a63b5ee029dd61e8 SHA-1: 1c5e6d69d6c5e8a5d6048618f8c525b96b568cd1 SHA-256: c4caba538d5d493b4b5b62720b23c178922b3a4d646e5b731bc1c2901b10b0bf
160 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File T1559 Component Object Model Hijacking T1559.001 Component Object Model Hijacking: Component Object Model and Distributed Component Object Model

The RTF document contains embedded OLE objects, specifically targeting the Equation Editor vulnerability. The presence of `RTF_EQUATION_EDITOR` and `RTF_OBJAUTLINK` heuristics indicates that the file is designed to exploit this known vulnerability, likely leading to the execution of a malicious payload. The `RTF_OBJUPDATE` heuristic further suggests that the OLE object is configured to activate automatically upon opening the document.

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.
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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 2 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off0000008d.bin
d53508201e7cd5e3105fe9c9ee6dcd5f2d0a62d584bd43bf8c89d3013114998e
rtf-objdata-decoded RTF \objdata at offset 0x8D 1462 bytes