Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 dced053899d4ca0b…

MALICIOUS

RTF / .DOC

50.0 KB First seen: 2023-09-14
MD5: 609beb41faca4628f4513fb3f74e59a8 SHA-1: b6ad901b6f63e08cb5c12f8c60162ed28d312471 SHA-256: dced053899d4ca0be0126761255d6fc06eb2ddbf72dcbb40b013faa1b2116d87
140 Risk Score

Malware Insights

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

The sample is an RTF document that contains an embedded OLE object, specifically leveraging the Equation Editor vulnerability. The document body includes a lure instructing the user to 'Enable editing', which is a common tactic to bypass security measures and execute embedded malicious content. The presence of RTF_OBJDATA and RTF_OBJUPDATE heuristics further indicates the exploitation of OLE object functionality.

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_off00003983.bin
e33071143a2aad821e240cd8a1a6b79a480cef56c7fd2df4bf2b1c8e6621e739
rtf-objdata-decoded RTF \objdata at offset 0x3983 1270 bytes