Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 3a8580e7cc52e8a5…

MALICIOUS

RTF / .DOC

2.07 MB First seen: 2022-03-22
MD5: fa7fe02db6e58035650e0d45ad830187 SHA-1: 2fbc7c49f6d9d1a01d4307102ed8ba395cca0a61 SHA-256: 3a8580e7cc52e8a5b48c1612bb26d91322e420c07ec1117b1009e13f9bc0992e
180 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File T1559.001 Component Object Model Hijacking

The RTF document contains an embedded OLE object that exploits CVE-2017-11882 through the Equation Editor component. The decoded object data contains what appears to be a VBScript, indicated by the presence of VBScript keywords and function calls. This script is likely responsible for downloading and executing a second-stage payload, although the full script content was truncated. The presence of the Equation Editor exploit and embedded script strongly suggests a malicious intent to compromise the user's system.

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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off0000129e.bin
4294874e305b86e93781449c11ba4e77b306abfe8c0f0d39ec9244266331f19e		 rtf-objdata-decoded RTF \objdata at offset 0x129E 86626 bytes
objdata_01_off000370c4.bin
bf6a136d18d93009433a6c5aab49cbf06a2db10a4d518c19158dd6b5c67bcc29		 rtf-objdata-decoded RTF \objdata at offset 0x370C4 462305 bytes

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