Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 575e4f0b824a7928…

MALICIOUS

RTF / .DOC

23.5 KB First seen: 2023-03-17
MD5: ea05f7ce4998ed1cdbac10b0f19fa433 SHA-1: 4a2b0b22314d8b83a266ac66eec5b3c07c3186d4 SHA-256: 575e4f0b824a7928e47d8eecd646b7aed2355ae8a1f85175b6ce092e26d43854
140 Risk Score

Malware Insights

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

The file is an RTF document that leverages an Equation Editor vulnerability, indicated by the RTF_EQUATION_EDITOR and RTF_OBJUPDATE heuristics. The SE_ENABLE_LURE heuristic confirms the presence of a lure to enable editing, which is a common tactic for macro-based malware delivery. The embedded OLE object data is likely a payload, but its specific nature cannot be determined from the provided evidence.

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_off000032c1.bin
ecd1fd64da76c0af48cd4561f1c1c0f6a28adb86c5bf79e844828d3021f0ff7b
rtf-objdata-decoded RTF \objdata at offset 0x32C1 1977 bytes