Malicious RTF — malware analysis report

Static analysis result for SHA-256 ac6ef8c9e74b01d6…

MALICIOUS

RTF

260.6 KB First seen: 2020-02-04
MD5: 2e90fd18b1a46563513856eb77bcafb8 SHA-1: 6e0303b160efdc7c6103317d426ad3c149915c2f SHA-256: ac6ef8c9e74b01d6ecc0ecadb57742250f4471fe69d9c6913c2501c996151877
140 Risk Score

Malware Insights

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

The RTF document contains OLE objects that are configured to automatically activate and load remote content, leveraging CVE-2017-0199 or CVE-2017-8759. This mechanism is used to download and execute a second-stage payload. The document body content appears to be financial transaction details, likely a lure.

Heuristics 4

  • 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
  • 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_off00000179.bin rtf-objdata-decoded RTF \objdata at offset 0x179 2608 bytes
SHA-256: 78c79f049c497d0682606da8cadd7078e67e2470b0e940e248d478969bf52fe2