Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 5f1ec634e330b8e0…

MALICIOUS

RTF / .DOC

33.1 KB First seen: 2023-06-10
MD5: 06781a15f52be8f2295542452db46b3d SHA-1: fa04d6e92789b3a3edfb719031a804c68b4dc5ec SHA-256: 5f1ec634e330b8e0bc657d51d9219898da9c78c890c805a1836f54fd8db70b43
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution T1204.002 User Execution: Malicious File

The sample is an RTF document containing an embedded OLE object, specifically targeting the Equation Editor vulnerability. The presence of \objupdate and SE_ENABLE_LURE heuristics indicates a strong attempt to trick the user into enabling content, which would then trigger the exploit. The document body itself is a lure, presenting itself as an academic assignment to encourage users to enable editing.

Heuristics 4

  • 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
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00004397.bin
5df75dc8b8e75b6b2fd29ccef0587dafef5759fb59cf012a463dfa93e0a01b48
rtf-objdata-decoded RTF \objdata at offset 0x4397 2098 bytes