Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 8736738c12e92859…

MALICIOUS

RTF / .DOC

35.4 KB First seen: 2022-12-23
MD5: 12ac77e8679888220ce781be670ae93b SHA-1: 85cd04b19d10e5f528f7d74b5cbb7573ee3bce49 SHA-256: 8736738c12e928595bbcee5a9f57edf6436a6569605ebbe2a242342b7c4d56eb
140 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.005 PowerShell

The sample is an RTF document containing OLE object data and specifically targets the Equation Editor vulnerability. The \objupdate heuristic indicates that the embedded OLE object is designed to be activated automatically, which is a common technique for exploiting vulnerabilities like the one in Equation Editor. The document body contains a lure to 'Enable editing', suggesting it's a malicious document designed to trick the user into triggering the exploit.

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_off000059fa.bin
9255ea0f338733cdf7e16f91ef181f9a1d17d529bfb78b7cb7bf057907b99f9d
rtf-objdata-decoded RTF \objdata at offset 0x59FA 1424 bytes