Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 9c0025252d0d3b01…

MALICIOUS

RTF / .DOC

18.0 KB First seen: 2022-10-06
MD5: 6c1f04a3f8f545ceb1682c069baa6c6f SHA-1: dbc1ccf4010eeb562b4ccee83fd490a614b3fc07 SHA-256: 9c0025252d0d3b01f91a6c3d9c3e13e6168226251cf8d8de9a6a5aa0d627510d
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File T1566 Phishing T1566.001 Phishing: Spearphishing Attachment T1059.005 Command and Scripting Interpreter: Visual Basic

The sample is an RTF document containing an OLE object with an Equation Editor ProgID, which is a known exploit vector. The document body contains a lure instructing the user to 'Enable editing', a common tactic to bypass macro security. The presence of `RTF_EQUATION_EDITOR` and `RTF_OBJUPDATE` heuristics strongly suggests exploitation of the Equation Editor vulnerability to achieve code execution.

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_off00001164.bin
0935fc72329f5bbb4ecc9c740b951f7b307670d0e78d8d26b5e14b37750a87a8
rtf-objdata-decoded RTF \objdata at offset 0x1164 1981 bytes