Malicious RTF — malware analysis report

Static analysis result for SHA-256 6e44d9eed2f9f5e6…

MALICIOUS

RTF

53.6 KB First seen: 2019-03-10
MD5: 27be0256647e1d2e3176518d49f9460a SHA-1: 4ac01ca8af842f09f02e7dbde6b187d855739e90 SHA-256: 6e44d9eed2f9f5e6139f4b6b39045294a9e5ac61ea00c2133b07c800221cd7c6
220 Risk Score

Malware Insights

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

The RTF document contains an OLE object that exploits the CVE-2017-11882 vulnerability in Microsoft Equation Editor. This vulnerability allows for arbitrary code execution, indicating a malicious intent to compromise the user's system. The presence of the exploit and the ClamAV detection strongly suggest this is a malicious document, likely delivered as a spearphishing attachment.

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_off00000b12.bin rtf-objdata-decoded RTF \objdata at offset 0xB12 5291 bytes
SHA-256: 9f47e778fbb662d897fbad00a11c9fad00cc771c20f74700efda7fc8d6c96d54