Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 8ecbdb78a788db07…

MALICIOUS

RTF / .DOC

29.8 KB First seen: 2023-04-15
MD5: d4c34bcc42a5368c829426b6632006aa SHA-1: e6126c119807b796e077e71c55ff5fae2f435acb SHA-256: 8ecbdb78a788db073bcb49eec45ce9127806673888d3bb22494f7c7c6a1cc455
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1059.005 PowerShell

The sample is an RTF document containing an embedded OLE object, specifically targeting the Equation Editor vulnerability. The 'SE_ENABLE_LURE' heuristic indicates the document prompts the user to enable editing, a common tactic to bypass security measures. The embedded object and the specific heuristic firing strongly suggest exploitation of the Equation Editor to achieve code execution.

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.
  • \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 1 \objdata section(s) — embedded OLE objects
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00004a54.bin
46dae6d6548dcee8232980c388fafcc100fa83cb3007fedc0a1fb902fe99c1f1
rtf-objdata-decoded RTF \objdata at offset 0x4A54 1622 bytes