Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 9535f82bc6c03a60…

MALICIOUS

RTF / .DOC

22.9 KB First seen: 2022-11-09
MD5: f1380fa458cbe7fe3826b174caeac05b SHA-1: 8b6d5fde016fdeb0194954ee6390ae07369e83dd SHA-256: 9535f82bc6c03a60efcd958df8a836e7295d0b34cc5c8a6154326a9477c7543f
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1566.001 Phishing: Spearphishing Attachment

The sample is an RTF document that contains embedded OLE object data and specifically targets the Equation Editor vulnerability. The document body includes a lure instructing the user to 'Enable editing', which is a common tactic to bypass macro security settings. The presence of RTF_EQUATION_EDITOR and RTF_OBJUPDATE heuristics strongly suggests exploitation of the Equation Editor vulnerability to achieve code 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_off000042e2.bin
ea462a700a99c3c86d40f00afed1b03e0e4db956e6990091546d78465405752c
rtf-objdata-decoded RTF \objdata at offset 0x42E2 1779 bytes