Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 747c08f3e6b45582…

MALICIOUS

RTF / .DOC

26.1 KB First seen: 2023-05-02
MD5: bf8678f9fed47a79e79d5e87ce588dab SHA-1: 2d29705fd6f2dd24954a75fa7dda6f119680e9f5 SHA-256: 747c08f3e6b45582d4c2227f0b64b216e6ab4849728c24099cec65cb16e0a885
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1059.005 Visual Basic

The file is an RTF document containing an embedded OLE object, specifically targeting the Equation Editor vulnerability. The presence of \objupdate and SE_ENABLE_LURE heuristics indicates the document attempts to trick the user into enabling content, which would likely trigger the exploit. The primary goal appears to be the execution of a secondary payload, though no specific download URL or script was directly extracted.

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_off00004b94.bin
aeda0126eedd173268ea98c598fbbb971da560ef8f0c407cac9d5f65fb64491f
rtf-objdata-decoded RTF \objdata at offset 0x4B94 1258 bytes