Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 db29b5d2b424eaaa…

MALICIOUS

RTF / .DOC

12.5 KB First seen: 2022-10-03
MD5: b71c27461a268a9924bc9023e6d8c9c7 SHA-1: 41b4173e0f0b113652f21e17f6d244018d306dd7 SHA-256: db29b5d2b424eaaa74615c5b004715afae1547951cb833b304a47bf170b568fc
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution T1204.002 Malicious File

The file is an RTF document containing an OLE object with a split Equation Editor ProgID, a known exploit technique. The \objupdate directive indicates an attempt to force OLE activation, and the document body contains a lure instructing the user to 'Enable editing'. This combination strongly suggests an attempt to exploit the Equation Editor vulnerability for initial 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_off00000ac5.bin
bb10ca3a690598a96709b585edebde2aa8e94b7c11c69dbdc30835667a90c333
rtf-objdata-decoded RTF \objdata at offset 0xAC5 1963 bytes