Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 4a0599949a34a868…

MALICIOUS

RTF / .DOC

33.8 KB First seen: 2023-05-24
MD5: 78457c4c3aa338d4ff0349415396207f SHA-1: 7b82111c8db8f32c171380d77180544b8a91adcd SHA-256: 4a0599949a34a868eef393234496b45220c9b99c3aaf0342d94b83e2cd61d5e1
140 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.005 Visual Basic

The RTF document contains an OLE object with an Equation Editor ProgID, and an \objupdate directive that forces OLE activation. The document body contains a lure instructing the user to 'Enable editing' to view the content. This combination strongly suggests an exploit targeting the Equation Editor vulnerability (CVE-2017-11882) 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_off0000441e.bin
152a58150ee610b159e06aaee4cc64054a42c867166e8540a26739bf9e474718
rtf-objdata-decoded RTF \objdata at offset 0x441E 1543 bytes