Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 ef716679efcb5ca3…

MALICIOUS

RTF / .DOC

3.8 KB
MD5: 95e7fc5e4d7bb5ae8791ffeaa4bf0c71 SHA-1: 0d4c92bfe315c1f75e6627a5c5c5930c0bc39543 SHA-256: ef716679efcb5ca3bee48b4738db6e440a0c74ecc73a234ada2495ff920fc61a
180 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The RTF document contains embedded OLE objects and specifically triggers the Equation Editor vulnerability (CVE-2017-11882). This exploit allows for arbitrary code execution upon opening the document. The presence of `eQUATION.3` as the class name further confirms the exploitation of this specific vulnerability. No scripts were extracted, but the exploit itself is sufficient to indicate malicious intent.

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_off00000087.bin
b84347025841a702a7b7574dc90f22c2069d9e2ba2aff51445b5c44a4dd9e881
rtf-objdata-decoded RTF \objdata at offset 0x87 1703 bytes