Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 bc74bc0afbb217e8…

MALICIOUS

RTF / .DOC

37.4 KB First seen: 2023-02-20
MD5: 2b7d05d0b2df07721c29694f4029c947 SHA-1: 16252448559f7c3d639b98b5ead83b7ba70b7124 SHA-256: bc74bc0afbb217e8ba0761e8b0e49b7a3c9945e5a83fa043d58679a2a8ea4231
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution: Malicious Link T1059.005 Command and Scripting Interpreter: Visual Basic

The RTF document contains an embedded OLE object with an Equation Editor ProgID, and uses \objupdate to force activation. The document body includes a lure instructing the user to 'Enable editing' to view the content. This combination strongly suggests an exploit targeting an OLE vulnerability, likely to download and execute 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_off00004ba4.bin
bb676c8cfccdbb94a518c3772278cdc70472fd685b959db56be56811e821d6ec
rtf-objdata-decoded RTF \objdata at offset 0x4BA4 1377 bytes