Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 0c173f05c5874204…

MALICIOUS

RTF / .DOC

4.1 KB
MD5: d80838713e733b28c56ba99e68c5d42e SHA-1: bb90c27279916600aff714bfe6b327bf9eac64b9 SHA-256: 0c173f05c58742047f9a97f1508a596a051d1b9f2fdbeb24bb70e35c857dd751
200 Risk Score

Malware Insights

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

The RTF document contains embedded OLE objects and specifically triggers the CVE-2017-11882 vulnerability related to Equation Editor. This indicates the file is designed to exploit a client-side vulnerability for code execution, likely delivered as a spearphishing attachment.

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.
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000000ac.bin
ce691e4126af27115cbfbe21be1bb4759d7cb006a5cf75bfc1431eefcbeb407d
rtf-objdata-decoded RTF \objdata at offset 0xAC 1777 bytes