Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 47be618f3bc46476…

MALICIOUS

RTF / .DOC

39.8 KB First seen: 2023-02-08
MD5: 7bef0db4752cfa72fa2a6b803399b404 SHA-1: e54ad9a8b00581c8523dfca5230878d72a84243f SHA-256: 47be618f3bc464769ed523f82df8383dfdd60f6c713c1662fbc5b57a068223c5
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1059 Command and Scripting Interpreter

The sample is an RTF document that contains an embedded OLE object with a suspicious ProgID, indicative of an Equation Editor exploit. The \objupdate directive further suggests that the embedded object is intended to be activated automatically. The document body contains a lure instructing the user to 'Enable editing', a common tactic to bypass security measures and trigger the exploit. The exploit likely leads to the execution of a second-stage payload.

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_off00005961.bin
641ca3a1974088e1c4286092a7442f7459cb9a24cbd92c80b8ef9f41c83c1c56
rtf-objdata-decoded RTF \objdata at offset 0x5961 1721 bytes