Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 2f2e6abb6e3f4f86…

MALICIOUS

RTF / .DOC

60.9 KB First seen: 2022-03-22
MD5: d137187d576f4358eb1964685d39d545 SHA-1: 94a3e67075fb4f098dace01ef582f3680832cc9d SHA-256: 2f2e6abb6e3f4f86677555aab7a9ea4c6bb71797832d81623e9c2f59a7710a35
160 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File T1559.001 Component Object Model Hijacking T1059.003 Command and Scripting Interpreter: Windows Command Shell

The RTF document contains embedded OLE objects, specifically triggering the Equation Editor vulnerability. The presence of \objupdate indicates that the embedded object is designed to be activated automatically upon opening, leading to the execution of arbitrary code. This is a common delivery mechanism for exploiting 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.
  • 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_off000000e2.bin
6ff130575521a52c8699e78e4aede2d231eef43f01820432c0b9404d5b4f7e55
rtf-objdata-decoded RTF \objdata at offset 0xE2 20836 bytes