Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 8893a5c23f09b252…

MALICIOUS

RTF / .DOC

3.18 MB Created: 2019-09-17 13:59:00
MD5: 038db1fe98b190bdb85793f6b39bbdd8 SHA-1: 3cb9e4978cdb7e817b769ed4f13eadeac76c0014 SHA-256: 8893a5c23f09b252b052cfafadce1065e5934c1f2877a4a11e98467faee05340
200 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.001 PowerShell

The file is an RTF document that leverages the Equation Editor vulnerability (CVE-2017-8759) to achieve code execution. The presence of OLE object data and the specific heuristic firings strongly indicate an exploit attempt. While no specific malware family is identified, the exploit mechanism is clear.

Heuristics 6

  • CVE-2017-8759 — MSXML SAX OLE activation critical CVE likely CVE_2017_8759
    RTF contains a hex-encoded OLE1 object for Msxml2.SAXXMLReader.6.0 followed by an embedded OLE compound document, and the document requests OLE activation. This matches the RTF staging shape used for CVE-2017-8759 SOAP/WSDL parser code injection.
  • Equation Editor CLSID critical RTF_EQUATION_EDITOR
    Equation Editor OLE CLSID found inside an OLE object — exploited by CVE-2017-11882 / CVE-2018-0802 / CVE-2018-0798
  • \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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off003150c9.bin
d40c495a24a0168df8f0f7d04f5b8a0b093eaf57fc12c8ff64578402df9a128e
rtf-objdata-decoded RTF \objdata at offset 0x3150C9 3732 bytes