Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 b4fa9ac87859d5af…

MALICIOUS

RTF / .DOC

3.9 KB First seen: 2022-03-21
MD5: 3de63b9d61a3e3ee3aaa8feff5ccb232 SHA-1: 860648eb74e598ebebe4584a9a586b2c5a529e8a SHA-256: b4fa9ac87859d5afb912d0b5638c7df3db8853646848cab1dc9737cf555b2d23
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The RTF document contains embedded OLE objects, specifically triggering heuristics related to Equation Editor vulnerabilities and automatic OLE activation. This indicates the file is designed to exploit a known vulnerability in the Equation Editor component to achieve arbitrary code execution upon opening.

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_off00000096.bin
4eee5d73bbc209c1e1a879f4808325c62d0551b11999fb3c1181d035bc25cc71
rtf-objdata-decoded RTF \objdata at offset 0x96 1751 bytes