Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 e3d50643213ef48f…

MALICIOUS

RTF / .DOC

30.0 KB First seen: 2023-03-25
MD5: 35a04d7b01eb67c705f1b41247c51f8a SHA-1: 8df5a131679473fc8febd7e36a49ef1b7c3c36c4 SHA-256: e3d50643213ef48f553607b5af99fe7e29207d6202c50c620ebb8e296fb68ddd
160 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1059.005 Service Execution

The RTF document contains an embedded OLE object and an \objupdate directive, indicating an attempt to activate it. The 'SE_ENABLE_LURE' heuristic confirms the document instructs the user to enable editing, a common tactic for malware droppers. This suggests the embedded object is likely a malicious payload designed to exploit a vulnerability, such as the Equation Editor vulnerability.

Heuristics 5

  • 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
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object
  • 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_off00004ac6.bin
a275fb4bdbede38db31565df486053635f57c5f8128a4a80729bdb990e7382d5
rtf-objdata-decoded RTF \objdata at offset 0x4AC6 1774 bytes