Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 bf3bb49c9bbbc6c3…

MALICIOUS

RTF / .DOC

44.8 KB First seen: 2022-12-19
MD5: 6fe191ab1c54718880e83292017bb0fa SHA-1: d2975432f328ff9cb22521ca9ea8c031b8fb0b08 SHA-256: bf3bb49c9bbbc6c3dab9d682d9ac9b99d5cfc60267e362d39c05a34246a4c446
140 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The RTF document contains an OLE object with a ProgID indicative of the Equation Editor vulnerability, and an \objupdate directive to force activation. The document body explicitly instructs the user to 'Enable editing' to view the content, a common lure for macro-based malware. The embedded OLE object is likely a secondary payload designed to exploit this vulnerability.

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_off00009373.bin
e6c443083ac33c2a83aee8527cf7f100a9f3519ee13e343f8d0f1cfb7e23fa93
rtf-objdata-decoded RTF \objdata at offset 0x9373 1761 bytes