Malicious RTF — malware analysis report

Static analysis result for SHA-256 8cdfdae871ac54d0…

MALICIOUS

RTF

1.92 MB Created: 2019-09-17 13:59:00 First seen: 2021-03-01
MD5: ebc2bbebf2c8d117344d8571756bd449 SHA-1: 1daea7c30e885f6ffd4a14900537eab4014c183f SHA-256: 8cdfdae871ac54d0aac1d11f5dd3e20f6ba994f57b46725c9de9287bb8ba872e
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_off001e058c.bin rtf-objdata-decoded RTF \objdata at offset 0x1E058C 1485 bytes
SHA-256: b54a5f0b20f61918661e3763a1408584ce5a007cda796e9e0fefccdb687e93a7