Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 aee43496026aadd3…

MALICIOUS

RTF / .DOC

93.0 KB First seen: 2023-09-18
MD5: 87dc64cd0d2d13f4897619c008540bcb SHA-1: 7f191350095893ebc3e1aa0e9e79dc083961e697 SHA-256: aee43496026aadd3bb0884c7fcd200758fde8c35940f0745628f4a0f480923c0
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

The file is an RTF document containing an embedded OLE object, specifically leveraging the Equation Editor vulnerability. The document body contains text designed to trick the user into enabling editing, which would activate the OLE object. This object is likely a malicious payload, as indicated by the RTF_EQUATION_EDITOR and RTF_OBJUPDATE heuristics.

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_off00003e6a.bin
fcad1624b368813118bbf63d830242eb3187c9bacaf614ae419e2149bfa16ad5
rtf-objdata-decoded RTF \objdata at offset 0x3E6A 2207 bytes