Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 6b5b84eb7e44975c…

MALICIOUS

RTF / .DOC

24.6 KB First seen: 2022-11-28
MD5: 6bb1bd40a70b7cef7f080219971f8003 SHA-1: 8c6accfd11b8878814135d3bf3abc549e0d01641 SHA-256: 6b5b84eb7e44975c37e121b4e62a5810920f895867bdb4357b0673d4cf9fd8f2
140 Risk Score

Malware Insights

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

The sample is an RTF document containing an embedded OLE object with a split Equation Editor ProgID, indicating an attempt to exploit CVE-2017-11882. The SE_ENABLE_LURE heuristic confirms the document instructs the user to enable editing, which would trigger the OLE object's activation via \objupdate. This is a common delivery mechanism for exploiting vulnerabilities like the Equation Editor flaw.

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_off00004d11.bin
797ac02b3af9443e0a08d43bc6631e1f64d42a04689b95301db280d5f3e845b8
rtf-objdata-decoded RTF \objdata at offset 0x4D11 1557 bytes