Malicious RTF — malware analysis report

Static analysis result for SHA-256 423da608394c5003…

MALICIOUS

RTF

201.0 KB First seen: 2018-07-08
MD5: 2d0decc675dae1cafde5d70e46237499 SHA-1: 9936c4b1924bba24aada1b18f149db31ec6aebea SHA-256: 423da608394c5003cda911a9bdf63725be12e957590e3e1761f83644d5c24f1a
120 Risk Score

Malware Insights

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

The RTF file contains OLE object data that is force-activated via \objupdate, triggering CVE-2017-0199 or CVE-2017-8759. This vulnerability allows for the automatic loading and execution of a second-stage payload embedded within the OLE moniker stream. The specific exploit targets are identified by the RTF_OLE2LINK_REMOTE_MONIKER_LOADER heuristic.

Heuristics 3

  • CVE-2017-0199 / CVE-2017-8759 (OLE2Link auto-activated remote loader) critical CVE related RTF_OLE2LINK_REMOTE_MONIKER_LOADER
    RTF embeds an OLE2Link object that is force-activated with \objupdate (no user interaction on open) and fetches a remote second stage — through an INCLUDETEXT/INCLUDEPICTURE field or the OLE object's own moniker. This is the OLE2Link auto-update attack path shared by CVE-2017-0199 (server returns an HTA/scriptlet) and CVE-2017-8759 (server returns a SOAP WSDL the .NET parser compiles). Office processes the fetched response through the same code path; the specific CVE depends on the now-unreachable server content type.
  • \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 2594 bytes
SHA-256: d117eae9d56c7ec0bf6859777238deecd00000c47bdbc783297c87adf6bb8ad8