Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 25f04a7c1774cff6…

MALICIOUS

RTF / .DOC

8.7 KB First seen: 2022-10-10
MD5: 539e53434998b0fc53443db6c19281a4 SHA-1: b7ea1a86f245c9917484407d0b8d6bd28ac5d949 SHA-256: 25f04a7c1774cff62216e5288fa486535a3ed6cf614f9b6650cba58716ced32e
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1566.001 Spearphishing Attachment T1204.002 Malicious File

The sample is an RTF document that contains an embedded OLE object with an Equation Editor ProgID, indicating an attempt to exploit the Equation Editor vulnerability (CVE-2017-11882). The ` tfobjdata` and ` tfobjupdate` heuristics confirm the presence and activation of this object. The `SE_ENABLE_LURE` heuristic suggests the document likely contains a prompt to enable content, a common lure for macro-based malware delivery.

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_off00000a10.bin
abda448006e1b6486c9ad32617125079385e9b21f80e43f239d96cc66204ef41
rtf-objdata-decoded RTF \objdata at offset 0xA10 1801 bytes