Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 891c2ce3c581f962…

MALICIOUS

RTF / .DOC

32.9 KB First seen: 2023-04-14
MD5: 0f2d271b0a4628d98c61769b6c54bfa7 SHA-1: 3abe6a0812d72bd28c68698dff86e81b987a4925 SHA-256: 891c2ce3c581f962cc747cc7a7c69e6725f9491b93c5996d092c3d2d8d5654ce
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1059 Command and Scripting Interpreter T1559 Component Object Model Hijacking

The sample is an RTF document that contains OLE object data and an embedded Equation Editor object, indicating an attempt to exploit a known vulnerability (CVE-2017-1188). The \objupdate directive further suggests that the embedded object is configured to execute automatically upon opening. The document body contains a lure to "Enable editing" to view the content, which is a common tactic for macro-based malware.

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_off0000504e.bin
dc68f1f862fc2c7f0e509dad3cb2889729050cdb0fb52c55ae9fae290c2b13a3
rtf-objdata-decoded RTF \objdata at offset 0x504E 1567 bytes