Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 6c49fb06dfe965c4…

MALICIOUS

RTF / .DOC

37.1 KB First seen: 2023-05-09
MD5: 22d293f6df6bf396a1eda845c2056316 SHA-1: ae030ddf62f8392918ab0bf2d4101d4d865e040d SHA-256: 6c49fb06dfe965c43e04fb518e026f5d1b86ab844797d76df6a8a13955099702
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution: Malicious Link T1059.005 PowerShell

The sample is an RTF document that leverages the Equation Editor vulnerability (RTF_EQUATION_EDITOR) to execute malicious code. It employs a lure (SE_ENABLE_LURE) to trick users into enabling content, a common technique for macro-based malware. The presence of OLE object data further indicates a potential exploit delivery mechanism.

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_off00004a67.bin
875f28f3b4154f2fcc5c8f15fd33f41677de8b829cf8d1e1ef2f6fe3ac51cd0d
rtf-objdata-decoded RTF \objdata at offset 0x4A67 1757 bytes