Malicious RTF — malware analysis report

Static analysis result for SHA-256 ec072bc2262af9b8…

MALICIOUS

RTF

261.1 KB First seen: 2019-09-30
MD5: cdbd993a9adf3bac6e9e3ee1d70e107c SHA-1: 990606c5b90b6f88e0a17141609c13426cf907f8 SHA-256: ec072bc2262af9b8c13ebf90400ff54884724eabc81c8004e5bf5a1e16203e07
120 Risk Score

Malware Insights

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

The RTF file contains an OLE object that is configured to automatically activate and load a remote resource, exploiting CVE-2017-0199 or CVE-2017-8759. This mechanism is used to download and execute a second-stage payload. The document body appears to be a financial document, likely a lure to trick the user into opening the malicious RTF file.

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_off00000152.bin rtf-objdata-decoded RTF \objdata at offset 0x152 2602 bytes
SHA-256: 6877900737988b77157247e0540e09352b37c0af5c767fe9c9a2766655d309b3