Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 c54917b909fd13ec…

MALICIOUS

RTF / .DOC

34.8 KB First seen: 2023-04-14
MD5: 331575dae5235b30a76fa7dfd7fce61d SHA-1: 3fc9b4c21d9601de72596588bab9c8c819c9811e SHA-256: c54917b909fd13ec72de8951273b7900c382c922d7722e26614f42a7dcb403cd
140 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object with a split Equation Editor ProgID, a known exploit vector. The \objupdate directive forces OLE activation, and the document body includes a lure to 'Enable editing'. This combination strongly suggests an attempt to exploit the Equation Editor vulnerability to execute a malicious 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_off000047a7.bin
dfaffa90b98186bcca45b29f8b3b98282f76588a93f2510ad1c8d9524fe26868
rtf-objdata-decoded RTF \objdata at offset 0x47A7 1465 bytes