Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 ebccdbaf7874f1b0…

MALICIOUS

RTF / .DOC

3.7 KB First seen: 2022-04-19
MD5: dabf150b9406586df8c0e8b8a3fba81c SHA-1: 49813cce330bcbcecdc6f8fc15ab0ac90a048e9c SHA-256: ebccdbaf7874f1b055a88daaa5c08773dc7426ceb7bc5fb9a1d6e5b04a22b4c5
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 Hijacking

The RTF document contains embedded OLE objects, specifically targeting the Equation Editor vulnerability. The presence of \objupdate and \objautlink heuristics indicates that the embedded object is designed to be automatically activated upon opening the document, leading to arbitrary code execution. This is a common delivery mechanism for exploits.

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_off000000e3.bin
632a21f07c5e9990cb573eb48d7121f5d24e76449085b11e784f806c4c61eab4
rtf-objdata-decoded RTF \objdata at offset 0xE3 1620 bytes