Malicious RTF — malware analysis report

Static analysis result for SHA-256 a3d44f3e28213b89…

MALICIOUS

RTF

4.75 MB
MD5: 4e89a9758ab58c0fddcb3daadb3fdb46 SHA-1: b7d458b48f1e7586395a18450f8620edacaa1aef SHA-256: a3d44f3e28213b89b70134c1dadbe11b69ffc5d7e9e3080d4da9392a7d5c7d3f
180 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The RTF document contains multiple high-severity heuristics indicating the presence and activation of OLE objects, including excessive hex-encoded data likely hiding a payload. The ".bin" file extracted from the OLE object data is substantial, suggesting it is the primary malicious component. The file's structure and heuristics strongly suggest it is delivered as a spearphishing attachment designed to exploit OLE vulnerabilities for initial execution.

Heuristics 5

  • Ole10Native stream in RTF OLE object high CVE related RTF_OLE10NATIVE_STREAM
    RTF contains an embedded OLE object with an Ole10Native stream. This is a strong payload-container signal and is related to Word/OLE exploit delivery, but it is not specific enough on its own to assign a CVE.
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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.
  • Large hex data blocks in OLE object high RTF_EXCESSIVE_HEX
    RTF contains ~4985KB of hex-encoded data inside \objdata sections — may hide a payload
  • OLE object data medium RTF_OBJDATA
    RTF contains 2 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00000087.bin
a6cbdba2677f9b79bc4c41008772715050c1de55167984efe0207fc0e10e2f3d
rtf-objdata-decoded RTF \objdata at offset 0x87 996423 bytes