Malicious RTF — malware analysis report

Static analysis result for SHA-256 85ccfc03926735b1…

MALICIOUS

RTF

306.5 KB First seen: 2019-03-10
MD5: 677ab3246483af2de959aa678090c59a SHA-1: 9faa89aa02ff76d66c369e05252f3511287bb707 SHA-256: 85ccfc03926735b1fcffd20cadd5b085295a39c73da6ead512620d69d652976c
120 Risk Score

Malware Insights

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

The RTF document contains an OLE2Link object that is automatically activated via \objupdate, exploiting CVE-2017-0199 or CVE-2017-8759. This mechanism is used to download and execute a second-stage payload from a remote source embedded within the OLE moniker stream. The document body content appears to be related to shipping and payment, potentially serving as a lure.

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_off000000d3.bin rtf-objdata-decoded RTF \objdata at offset 0xD3 3115 bytes
SHA-256: 7a8670d06bce6688f6c5fd36f027826a9b76a99f51d3f66a00675855306ce34e