Malicious RTF — malware analysis report

Static analysis result for SHA-256 2e683814a033f7b4…

MALICIOUS

RTF

318.0 KB First seen: 2019-03-10
MD5: 4365ff6f8b442e66dbb1a897e01e4a66 SHA-1: 9e4ce7ff129f5d100f6e0fea9fded7a1b7c71cea SHA-256: 2e683814a033f7b49f0b3707f5befc4f7d2371a316cf87e49af906c12109c322
120 Risk Score

Malware Insights

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

The RTF document contains an OLE object that is force-activated via \objupdate, triggering CVE-2017-0199 or CVE-2017-8759. This vulnerability allows the embedded OLE object to load and execute a remote payload. The specific payload and its origin are not statically determinable, but the exploit mechanism is clear.

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_off0000017a.bin rtf-objdata-decoded RTF \objdata at offset 0x17A 3119 bytes
SHA-256: 196c2078cd37a3b6fd5ebd26063aa7bddac75e366d347470320cec5a8be2dd6e