Malicious RTF — malware analysis report

Static analysis result for SHA-256 d6cf18ee44f1f9f0…

MALICIOUS

RTF

1.34 MB Created: 2019-09-17 13:59:00 First seen: 2021-05-10
MD5: 03cb3050e1b91cd600465c0b60da7df6 SHA-1: ff4749383cf90fad84f11cfc1997d72c1baca800 SHA-256: d6cf18ee44f1f9f039074d98c01ccc2da11f827349bf3760be6a5b662ec80708
182 Risk Score

Heuristics 6

  • Obfuscated Equation Editor ProgID + activation critical CVE related RTF_EQUATION_EDITOR
    RTF decodes to an Equation.3 ProgID from top-level \objdata hex after nested RTF junk groups are ignored, and the document also contains \objemb plus \objupdate activation. This is an obfuscated Equation Editor exploit surface associated with CVE-2017-11882 / CVE-2018-0802 families, but no exact malformed MTEF CVE primitive was recovered from this object.
  • 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.
  • \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 1 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://schemas.microsoft.com/office/word/2003/wordml In RTF body

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off0014626a.bin rtf-objdata-decoded RTF \objdata at offset 0x14626A 1478 bytes
SHA-256: 8bb9006cab635f31762ebb9c7e7e3b9c1e518fd7df8861441973cff0c85e7f7f