Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 82abc4daffdd8076…

MALICIOUS

RTF / .DOC

14.9 KB First seen: 2022-10-04
MD5: 54035260e3cc5731c554b21d83a060e4 SHA-1: 69d47fa27850ed01d4ab7ae17e695504652a0d73 SHA-256: 82abc4daffdd8076a7ad954f4b8d8422e74733dd8ec374afc95deebedec0c186
140 Risk Score

Malware Insights

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

The sample is an RTF document containing an embedded OLE object, specifically exploiting the Equation Editor vulnerability. The document body contains a lure instructing the user to 'Enable editing' to view the document, a common tactic to bypass macro security. The presence of RTF_OBJDATA and RTF_OBJUPDATE heuristics further indicates the exploitation of OLE object vulnerabilities.

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_off00001347.bin
7f6a9ceb25a4ec94deba1c8e4801c39324b26368a0c787e67976c1a8f01ec37e
rtf-objdata-decoded RTF \objdata at offset 0x1347 1904 bytes