Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 25966cc19f04cbbd…

MALICIOUS

RTF / .DOC

4.1 KB First seen: 2022-05-27
MD5: afaa3f4a9a241593ea30e05773c22980 SHA-1: 1d9dabc7f48e7d3c50c3d7d36a371be6bb63746d SHA-256: 25966cc19f04cbbdacdf04249247d606c037cb527669addbfb0d52e0cd948519
121 Risk Score

Malware Insights

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

The sample is an RTF document containing embedded OLE object data. Heuristics indicate a critical vulnerability in Equation Editor was targeted, and an \objupdate directive forces OLE activation. This suggests the file is designed to exploit the Equation Editor vulnerability to achieve arbitrary code execution upon opening.

Heuristics 3

  • 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 2 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off0000006a.bin
83f57a06de1859081449771a9c7533b962dc3b005983397e5777e5a8aefd170b
rtf-objdata-decoded RTF \objdata at offset 0x6A 1746 bytes