Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 1087038651650746…

MALICIOUS

RTF / .DOC

16.9 KB
MD5: 88377d62e1243aed915f37dfaf01bb18 SHA-1: ec0eef67c61420eb6bb97eafc060fe23d3275be7 SHA-256: 1087038651650746e9b8c2aececa05dd41fe91b7a027a4225bd9bf01674aa877
280 Risk Score

Malware Insights

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

The sample is an RTF document containing embedded OLE object data, specifically triggering critical heuristics for Equation Editor and CVE-2017-11882. This indicates the file is designed to exploit a vulnerability in the Equation Editor component to achieve code execution. The presence of ".objupdate" further suggests an attempt to automatically activate the embedded object, likely to download and execute a secondary payload.

Heuristics 6

  • CVE-2017-11882 — Equation Editor FONT record overflow critical CVE likely CVE_2017_11882
    Equation Editor MTEF contains an overlong FONT typeface field, the vulnerable copy primitive for CVE-2017-11882. This is stronger evidence than the Equation Editor CLSID alone because it identifies the malformed record that drives code execution in EQNEDT32.EXE.
  • Equation Editor CLSID critical RTF_EQUATION_EDITOR
    Equation Editor OLE CLSID found inside an OLE object — exploited by CVE-2017-11882 / CVE-2018-0802 / CVE-2018-0798
  • ClamAV: Rtf.Exploit.CVE_2017_11882-6584355-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Rtf.Exploit.CVE_2017_11882-6584355-1
  • 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.
  • OLE object data medium RTF_OBJDATA
    RTF contains 1 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00001e83.bin
2e6300238f1a35096c20750ba58fcc22f8866501c2b23465c8286855699fd173
rtf-objdata-decoded RTF \objdata at offset 0x1E83 4670 bytes