Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 c891b6bb21fda17e…

MALICIOUS

RTF / .DOC

4.0 KB First seen: 2022-07-28
MD5: c80d90777ecb011d8f7ff5c85728a150 SHA-1: fa43c4674a0ded98466a1e9048903352b82b8131 SHA-256: c891b6bb21fda17e3149d2d1897fda2bca8f1453d5ddb251e3479f48bb1e771c
180 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1559.001 Component Object Model Hijacking

The RTF file contains embedded OLE objects, specifically triggering the CVE-2017-11882 vulnerability related to Equation Editor. The presence of \objupdate and \objdata sections indicates an attempt to force OLE activation and execute embedded malicious content, likely leading to arbitrary code execution.

Heuristics 5

  • 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.
  • 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 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_off0000005f.bin
8c08b0d8f180051416f4ded1f7aaad4e4e8ada40254578da6fb6534f1ad64ac3		 rtf-objdata-decoded RTF \objdata at offset 0x5F 1691 bytes

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