Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 15911c5de84771c7…

MALICIOUS

RTF / .DOC

24.0 KB First seen: 2022-12-23
MD5: d68448814184ca9a1386fba6c212a034 SHA-1: 0d6c96d9bdc920752b72849736161395f6b1e63b SHA-256: 15911c5de84771c7fe086f3425bd80ed601afb76604b747909f91eaa8b38aec5
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution T1059.005 PowerShell

The sample is an RTF document containing an embedded OLE object that leverages the Microsoft Equation Editor vulnerability. The document body contains a lure instructing the user to 'Enable editing', which, if acted upon, would likely trigger the exploit. The presence of RTF_EQUATION_EDITOR and RTF_OBJUPDATE heuristics strongly suggests exploitation of this component.

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_off00004ed0.bin
22a05a07046d2cbbd7a56360174d99b2df5427f3e0f990d14dc33421f3981128
rtf-objdata-decoded RTF \objdata at offset 0x4ED0 1445 bytes