Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 fc88bd2fcdf6c916…

MALICIOUS

RTF / .DOC

108.9 KB First seen: 2023-08-22
MD5: efa256b14c2fb7b7eb9a63986269f7d6 SHA-1: 09ec52d50e86e4d43adca60aadb8e1439041978e SHA-256: fc88bd2fcdf6c916d4c7e0ecdd3b75bcdae0ea8f950b1aa300df01ab801e0863
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution T1204.002 Malicious File T1566 Phishing T1566.001 Spearphishing Attachment T1059 Command and Scripting Interpreter

The sample is an RTF document that leverages an Equation Editor vulnerability, indicated by the RTF_EQUATION_EDITOR and RTF_OBJDATA heuristics. The document body contains text about financial audits and includes a lure to 'Enable editing' to bypass security measures. The RTF_OBJUPDATE heuristic suggests that the embedded OLE object is designed to be activated automatically, likely to exploit the Equation Editor vulnerability and execute a malicious payload.

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_off00002fe9.bin
7f3f6d3c85e2c798e841ceae586182f4993d44e0cf19e6b8bdd82e6d706e7b2e
rtf-objdata-decoded RTF \objdata at offset 0x2FE9 1675 bytes