Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 ac51aa36d4e6d697…

MALICIOUS

RTF / .DOC

46.7 KB First seen: 2023-02-21
MD5: 31120b3cff41aa469eeab7f3b8592010 SHA-1: ec996389bbf24f81ff0d5187e1f5fa5c7632d392 SHA-256: ac51aa36d4e6d6974b7ed89ac9c75258578fed36bc18e8a69af91e1d7e494f2f
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution: Malicious Link T1059.005 PowerShell

The sample is an RTF document that contains OLE object data and specifically targets the Equation Editor vulnerability. The document body includes a lure instructing the user to 'Enable editing', a common tactic for macro-based malware. The presence of RTF_EQUATION_EDITOR and RTF_OBJUPDATE heuristics strongly indicates exploitation of this component 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_off00005303.bin
1bbcabbc7c18295f3375c26bbd138bf6193dda24d03ae833e9e1ed08ff04d7b5
rtf-objdata-decoded RTF \objdata at offset 0x5303 1940 bytes