Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 6ca7a502156729bb…

MALICIOUS

RTF / .DOC

24.0 KB First seen: 2022-11-23
MD5: 9bbab3c38196d24f9924f5fdf7971940 SHA-1: b582ab4810cdcf6941e4ca223f36a7875a31e5a2 SHA-256: 6ca7a502156729bb68d85de9a01ddfe2578c5dc0b5c983bd6904c1575286b88e
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 an embedded OLE object, specifically targeting the Equation Editor vulnerability. The ".objupdate" directive indicates that the OLE object will be activated automatically upon opening, which is a common lure to trigger the exploit. The document body contains a generic lure to 'Enable editing', further supporting the malicious intent.

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_off000041d2.bin
caeebd50229e1448e6ce85ce0f11b3bd01d917bbdad35573c8a748113dd4cd0e
rtf-objdata-decoded RTF \objdata at offset 0x41D2 1714 bytes