Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 ba7d842e156b9670…

MALICIOUS

RTF / .DOC

39.8 KB First seen: 2023-07-17
MD5: 89a3c23f527d57c3de50191389a88b52 SHA-1: 804d6a58ed06b1823230013d7c9636be7455d285 SHA-256: ba7d842e156b96709b95f308c3ee31fe5e0478d92ed714bc5a5d1322b281f579
140 Risk Score

Malware Insights

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

The file is an RTF document containing an embedded OLE object with a specific Equation Editor ProgID, identified by the RTF_EQUATION_EDITOR heuristic. The RTF_OBJUPDATE heuristic indicates that the object is configured to activate automatically upon opening or when editing is enabled, which is further suggested by the SE_ENABLE_LURE heuristic indicating a prompt to enable editing. This strongly suggests an attempt to exploit a vulnerability, likely related to the Equation Editor, to execute a malicious payload.

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_off00004746.bin
b0d11c344bfa8445f58eca8dd0a117f4913c9d22f8107d316d3997462cbc9100
rtf-objdata-decoded RTF \objdata at offset 0x4746 1840 bytes