Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 d0818cb4a7a30983…

MALICIOUS

RTF / .DOC

25.9 KB First seen: 2022-11-09
MD5: 7577d920ae57cb318bad9c7925daf198 SHA-1: be213fc92ca2be8c6e35c79b4a3b33e861137b15 SHA-256: d0818cb4a7a309836b20152271e52c615eb4593c115a160e7ac457e615579df7
200 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.005 Visual Basic

The file is an RTF document that contains an embedded OLE object with an Equation Editor ProgID, a known exploit vector. The \objupdate directive forces the activation of this object, triggering the exploit. The document also contains a lure instructing the user to 'Enable editing', a common tactic to bypass security measures. ClamAV detected this as Rtf.Malware.Agent-9977323-0, indicating a known malicious RTF variant.

Heuristics 5

  • 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.
  • ClamAV: Rtf.Malware.Agent-9977323-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Rtf.Malware.Agent-9977323-0
  • \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_off000050f9.bin
747600fcc91300efe0894d20f79f6df94ac92326d63948550cb53ce4816a0b5e
rtf-objdata-decoded RTF \objdata at offset 0x50F9 1630 bytes