Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 4d630c5830d0317e…

MALICIOUS

RTF / .DOC

18.7 KB
MD5: 0265fb3fdca25aa9bc5c0fd495e3590a SHA-1: a1a171861cf974361c0e3bd9f64f972b95feb021 SHA-256: 4d630c5830d0317ebe89a54d9575a3d63449b2ae3a459dd7dabcf6d7eb3107c5
120 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The sample is an RTF document that contains an embedded OLE object, specifically targeting the Equation Editor vulnerability. The ".objupdate" directive indicates that the embedded object will be activated automatically upon opening the document, leading to the exploitation of the Equation Editor. This is a common delivery mechanism for malware that aims to execute arbitrary code.

Heuristics 3

  • 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 1 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off0000237e.bin
9d77e1a5061c8f22905dfaf82a6a800b2e87eea8f944e0ddd296862f3faa657c
rtf-objdata-decoded RTF \objdata at offset 0x237E 1649 bytes