Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 fc3b183952180688…

MALICIOUS

RTF / .DOC

120.3 KB First seen: 2024-05-22
MD5: 237e25bae91107e3eb445afe566378e8 SHA-1: e1b858a7764277cb94920750cddf5ee3f058caf6 SHA-256: fc3b18395218068895ed815c742fdb1a2b93daf03d4c768b5ac989d95339fe83
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File T1566 Phishing T1566.001 Phishing: Spearphishing Attachment T1059 Command and Scripting Interpreter T1059.005 Command and Scripting Interpreter: Visual Basic

The file is an RTF document containing an embedded OLE object, specifically leveraging the Equation Editor vulnerability. The document body contains a lure to 'Enable editing' and implies a need to enable macros. The presence of RTF_OBJDATA and RTF_OBJUPDATE heuristics further indicates the exploitation of OLE object functionality to execute malicious code. The primary attack vector appears to be the exploitation of the Equation Editor within the OLE object.

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_off00008d51.bin
d944bd22ab70447930cc8e648c74362e03207dec09cb8e174cda75b972bbe95e
rtf-objdata-decoded RTF \objdata at offset 0x8D51 1787 bytes