Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 a127250c7ed8bc17…

MALICIOUS

RTF / .DOC

43.8 KB First seen: 2023-09-04
MD5: c7a7d651d94a44351ef2341d4d3a0f0b SHA-1: 41c17a2bc4f01c97d4a0d9749ff2db8c4591f66c SHA-256: a127250c7ed8bc171291a02de784b956e24db5a0f9ca3393d18d9642258f2cf7
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution T1204.002 Malicious File T1059 Command and Scripting Interpreter T1059.005 Visual Basic

The sample is an RTF document that contains OLE object data and specifically targets the Equation Editor vulnerability. The presence of \objupdate indicates an attempt to automatically activate the embedded object, and the heuristic SE_ENABLE_LURE suggests the document prompts the user to enable editing. This combination strongly indicates an exploit delivery mechanism designed to execute malicious code.

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_off0000303b.bin
60e78882b8ec3e02ca89790c00efe84977aa3a95324bb34ca547dcfcacc6addc
rtf-objdata-decoded RTF \objdata at offset 0x303B 1472 bytes