Malicious RTF — malware analysis report

Static analysis result for SHA-256 bc6182cccbc9bff6…

MALICIOUS

RTF

8.2 KB First seen: 2019-12-09
MD5: 62f4545cd2fea1e9e7af2fe2e35309cd SHA-1: f45481d4155d0ad46682c1e43589e5245a0a1e3f SHA-256: bc6182cccbc9bff6017f6c1c7e1869f6f717c2f8dc126de5ec2938b74595d7cb
260 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 component. This exploit allows for arbitrary code execution upon opening the document, likely delivered via spearphishing.

Heuristics 6

  • 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
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off0000003a.bin rtf-objdata-decoded RTF \objdata at offset 0x3A 4159 bytes
SHA-256: 6de39c5202994375eb6bd81f264e915c9141e8332f2ab975f956f45f089448c2