Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 908a9cf82625cce5…

MALICIOUS

RTF / .DOC

33.1 KB First seen: 2023-06-06
MD5: 55c890436be060d5f660269c397ad056 SHA-1: 50b51439c7dc4bd9cf1b8b12b5a435fee37c8270 SHA-256: 908a9cf82625cce540d18ae96a6f39acb5613b664e9f6e76856032d24b8db3e6
140 Risk Score

Malware Insights

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

The sample is an RTF document containing an embedded OLE object, specifically targeting the Equation Editor vulnerability. The 'SE_ENABLE_LURE' heuristic indicates the document prompts the user to enable editing, which is a common social engineering tactic to bypass security measures. The embedded OLE object and the specific Equation Editor targeting suggest the document is designed to exploit a known vulnerability to deliver 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_off0000445e.bin
2a0f396c92b4123b94f6635cdfca06cc768a0612466490902b317d66066e2f91
rtf-objdata-decoded RTF \objdata at offset 0x445E 2091 bytes