Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 1ce6939a2a14d23d…

MALICIOUS

RTF / .DOC

19.1 KB
MD5: 4d332f00dd2d63fb44febc2bb5b13809 SHA-1: f1b47473d62614a72217c456b504cf2a2328b01b SHA-256: 1ce6939a2a14d23d0b62c13bec80ab93dba7667f867bb05b905476bdec9d5c33
180 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 User Execution: Malicious File T1203 Exploitation for Client Execution

The sample is an RTF document containing a specially crafted OLE object designed to trigger CVE-2017-11882. The heuristic firings for RTF_EQUATION_EDITOR and CVE_2017_11882_ACTIVATION_RELATED explicitly identify the presence of an embedded object with the class 'eQUAtIoN.3' which is the primary indicator of this exploit. No second-stage payload or C2 infrastructure was extracted from the binary object, but the exploit mechanism is highly characteristic of a darah-style delivery mechanism.

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_off00000cc1.bin
918326db4e9c22d3641312303d42052187eb996a006fb87590bf4d2e3968f3a5		 rtf-objdata-decoded RTF \objdata at offset 0xCC1 1951 bytes

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