Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 a4241d238344019a…

MALICIOUS

RTF / .DOC

1.75 MB
MD5: e2254c3d7c2dbc0647d23747dcdb7364 SHA-1: 524507972fed3f61ee4b54cf521aacd7056aa65b SHA-256: a4241d238344019a941dca7f4b20e3258a363afdfb2dd4a75f09bb41f0a676f6
240 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Phishing: Spearphishing Attachment

The RTF document contains an embedded OLE object that leverages the CVE-2017-11882 vulnerability in the Equation Editor. This exploit is designed to execute arbitrary code, likely to download and run a secondary payload. No document body text or scripts were extracted, but the critical heuristics strongly indicate exploitation of this specific CVE.

Heuristics 6

  • Equation Editor OLE1 native payload — CVE-2017-11882 related critical CVE related CVE_2017_11882_RELATED
    RTF decodes to an OLE1 Equation.3 embedded object whose native data is large and payload-like, and \objupdate requests automatic activation. This is the delivery shape used by Equation Editor RCE documents such as CVE-2017-11882/CVE-2018-0802, but the malformed MTEF record needed for exact 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.
  • Large hex data blocks in OLE object high RTF_EXCESSIVE_HEX
    RTF contains ~1834KB of hex-encoded data inside \objdata sections — may hide a payload
  • OLE object data medium RTF_OBJDATA
    RTF contains 1 \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_off0000003d.bin
08ad3c2305660830ae0e409c5c54dda9c061b82f519880005c6e31c33c9d5bbf		 rtf-objdata-decoded RTF \objdata at offset 0x3D 917132 bytes

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