Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 1b7b7cb77586a27c…

MALICIOUS

RTF / .DOC

11.6 KB
MD5: db5c6881c157ca44109f0422b084ece5 SHA-1: 2ce78059618173840fe6e23cbf1accbf9b824a88 SHA-256: 1b7b7cb77586a27ceecd9f367f0c44e7d7792d584e0f785f5babd231dadfa91c
180 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.001 PowerShell

The sample is an RTF document that leverages the CVE-2017-11882 vulnerability by exploiting Microsoft Equation Editor. This vulnerability allows for arbitrary code execution when the document is opened. The presence of OLE object data and specific Equation Editor ProgIDs strongly indicates this exploit method. No specific malware family could be identified, but the attack pattern is clear.

Heuristics 5

  • Obfuscated Equation Editor ProgID + activation critical CVE related RTF_EQUATION_EDITOR
    RTF decodes to an Equation.3 ProgID from top-level \objdata hex after nested RTF junk groups are ignored, and the document also contains \objemb plus \objupdate activation. This is an obfuscated Equation Editor exploit surface associated with CVE-2017-11882 / CVE-2018-0802 families, but no exact malformed MTEF CVE primitive was recovered from this object.
  • Equation Editor activation — CVE-2017-11882 related high CVE related CVE_2017_11882_ACTIVATION_RELATED
    RTF decodes to an Equation.3 ProgID and requests OLE activation with \objemb plus \objupdate. This reaches the legacy Equation Editor attack surface used by CVE-2017-11882/CVE-2018-0802 documents, but the malformed MTEF/native payload needed for stronger attribution was not recovered.
  • \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 2 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00001a69.bin
34d58d849bb6ae1560e4584f93ce094b6c5991830f68dfcfd7d18690b48ab259		 rtf-objdata-decoded RTF \objdata at offset 0x1A69 1594 bytes

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