Malicious RTF — malware analysis report

Static analysis result for SHA-256 7aba295d3ad66596…

MALICIOUS

RTF

35.7 KB First seen: 2018-12-09
MD5: a25449330a015228a6db21caaa12cb81 SHA-1: 63cc3fe1e0fefffad6ca25aae07345d4cbfb7476 SHA-256: 7aba295d3ad66596c08db02f0d7d43baeb99c05c7e24ef1e03113597f7c6e3a3
220 Risk Score

Malware Insights

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

The RTF document contains embedded OLE object data, specifically triggering the CVE-2017-11882 vulnerability in Microsoft Equation Editor. This exploit allows for the execution of arbitrary code, indicating a malicious intent to compromise the user's system. The presence of the OLE object and the specific CVE exploit are strong indicators of this attack pattern.

Heuristics 5

  • 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.
  • ClamAV: Doc.Exploit.CVE_2017_11882-6934206-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Exploit.CVE_2017_11882-6934206-0
  • 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_off0000003f.bin rtf-objdata-decoded RTF \objdata at offset 0x3F 4146 bytes
SHA-256: df4f21724365f80c75e623ca5c606ce203e367e5b26edc8f223d86da00da42d7