Malicious RTF — malware analysis report

Static analysis result for SHA-256 db3da422811cd900…

MALICIOUS

RTF

9.2 KB First seen: 2019-10-30
MD5: 7be24bbb5076b12dd2e3b31c65b061a4 SHA-1: 66a8360cfd99a90d0c29d7d60ce40a72c03f6ed8 SHA-256: db3da422811cd90086791c65687686aa0512cf35f7a9e57004d789e772d10034
240 Risk Score

Malware Insights

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

The sample is an RTF document that contains embedded OLE object data. Heuristics indicate a critical vulnerability in Equation Editor (CVE-2017-11882) is being exploited. This vulnerability allows for arbitrary code execution when the document is opened, likely delivered via spearphishing.

Heuristics 5

  • Equation Editor CLSID critical CVE likely RTF_EQUATION_EDITOR
    Equation Editor OLE CLSID found inside an OLE object — exploited by CVE-2017-11882 / CVE-2018-0802 / CVE-2018-0798
  • 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
  • \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_off0000003c.bin rtf-objdata-decoded RTF \objdata at offset 0x3C 4668 bytes
SHA-256: 6cb7bd2a3b5d92eb9cbea439ab41cb70eac7db4d47529b9902f3aff2beca4ef4