Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 36936433537e63b8…

MALICIOUS

RTF / .DOC

23.6 KB First seen: 2023-01-24
MD5: ecf1860968271480d768159b98637d70 SHA-1: 92a976c43f2220d7ce3a065a9603c876c759de29 SHA-256: 36936433537e63b87d4706d1cfcffd572f3d19711ed627a60ed4ca2ba28ba415
140 Risk Score

Malware Insights

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

The sample is an RTF document containing an OLE object with a split Equation Editor ProgID, indicating exploitation of CVE-2017-11882. The document body contains a lure instructing the user to 'Enable editing' to view the content, which is a common tactic for macro-based malware delivery. The presence of \objupdate further suggests automatic activation of the embedded OLE object.

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_off00004634.bin
bb6a511edc7055302d1e7b3aa514b03c7d6994bcbaa3a9948a5f44b4c827f965
rtf-objdata-decoded RTF \objdata at offset 0x4634 1759 bytes