Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 849354bbafaedc66…

MALICIOUS

RTF / .DOC

11.8 KB First seen: 2022-10-31
MD5: 984847d0c97054c4bbdf18d396559901 SHA-1: 7e0b44e0f222ddaa72c603e68083a1cd81854416 SHA-256: 849354bbafaedc663e3d45d936b08c86a759b8da9e79d5865a4a20b2b5f0c9c8
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution T1204.002 Malicious File T1566 Phishing T1566.001 Spearphishing Attachment

The file is an RTF document that uses an OLE object containing an Equation Editor exploit. It employs a lure to trick the user into enabling editing and macros, a common technique for malware droppers. The presence of \objdata and \objupdate heuristics strongly suggests an embedded exploit designed for execution upon user interaction.

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_off00001a72.bin
3491a727f5e87afc3ad49e6756e7835568f7e9f5579f06e919d2e6206d9addf2
rtf-objdata-decoded RTF \objdata at offset 0x1A72 1717 bytes