Malicious RTF — malware analysis report

Static analysis result for SHA-256 1155564b6ee7d0b4…

MALICIOUS

RTF

148.7 KB First seen: 2019-12-09
MD5: a25ea985eedcdc01bacbb89486d1e26d SHA-1: c529e7fdce35625992e459c8f6ae177ff5a8729a SHA-256: 1155564b6ee7d0b42aea856d44776d4fdb635ebd2e3d7db8433233b9d284d930
220 Risk Score

Malware Insights

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

The RTF file contains embedded OLE object data and specifically triggers the CVE-2017-11882 vulnerability within the Equation Editor. This indicates the file is designed to exploit this known vulnerability for client-side code execution, likely delivered as a spearphishing attachment.

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.
  • 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_off00000070.bin rtf-objdata-decoded RTF \objdata at offset 0x70 46675 bytes
SHA-256: 8e3ce5463a782047a31be03d303dd3ba282cdc66e4ed6bdfe578b7fec0ac03f5