Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 ae8912485487bbd9…

MALICIOUS

RTF / .DOC

55.7 KB First seen: 2023-08-07
MD5: 3db137b68ac902eaefc048a4d04c89c0 SHA-1: c2127b40577e2a59ea0d0dea98f4fa96a77fdd8a SHA-256: ae8912485487bbd99f7defde38ab0da19ed679c5eec9d0272ec8ea69fc7d191d
140 Risk Score

Malware Insights

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

The file is an RTF document containing an embedded OLE object with a split Equation Editor ProgID, a known exploit technique. The document body contains a lure instructing the user to 'click Enable editing', which, combined with the ".objupdate" directive, suggests an attempt to trigger the exploit. The exploit likely leads to the download and execution of a secondary payload.

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_off000035cc.bin
844f761fd490d98d6d6d1ddffa7b910e9006a6dadead4740640512abd4c8bf5f
rtf-objdata-decoded RTF \objdata at offset 0x35CC 1407 bytes