Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 d9cdba3d4d8e36b7…

MALICIOUS

RTF / .DOC

18.7 KB
MD5: ce759eae3b14f4f86f1a36f67dfc55a0 SHA-1: 559c9da97b662027393a37ed4e7e37326b1066f5 SHA-256: d9cdba3d4d8e36b7536994f9bf884d0104c0c45063d0d0d2baab6225164eb9fb
120 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.001 PowerShell

The sample is an RTF document that contains embedded OLE objects and triggers an object update. The critical heuristic firing 'RTF_EQUATION_EDITOR' indicates exploitation of the Equation Editor vulnerability. This technique is commonly used to achieve arbitrary code execution, typically for downloading and executing a second-stage payload. No specific family could be identified from the available evidence.

Heuristics 3

  • 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 2 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00001d73.bin
ed49567b9c15e9df8bb88da64cd4fd778f6b755f4603ad7d06d9143445d9dde1
rtf-objdata-decoded RTF \objdata at offset 0x1D73 1505 bytes