Malicious RTF — malware analysis report

Static analysis result for SHA-256 da175c8dcd9dcb64…

MALICIOUS

RTF

9.1 KB First seen: 2019-05-16
MD5: d26620edc2781d06c7b56af7c19f31f7 SHA-1: 09eb250b2d760c07e31d4c4772c23c664a17f310 SHA-256: da175c8dcd9dcb64f572629b262fd701607ff773f22a96fac598257c0195ab08
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 an embedded OLE object. Heuristics indicate a critical vulnerability, CVE-2017-11882, related to the Equation Editor, which is known to allow for arbitrary code execution. This exploit is typically delivered via spearphishing attachments.

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 4650 bytes
SHA-256: 03b723c0b8292efbdc865f17d3900df192493e62df58925d081948d533bd7575