Malicious RTF — malware analysis report

Static analysis result for SHA-256 4e6ced6bb7f451d7…

MALICIOUS

RTF

17.8 KB First seen: 2017-11-13
MD5: ab2ecbeeeb9b5d62efd98c903ae2240b SHA-1: 214a59465b356c0b33d24b2714f640ea347287cc SHA-256: 4e6ced6bb7f451d7c9f257d6f7cab3d6232984ae46105f823146a5dc4a72878f
162 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 designed to download and execute a second-stage payload. The document also contains a lure to enable editing, which is a common tactic for malware droppers.

Heuristics 6

  • 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
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://schemas.microsoft.com/office/word/2003/wordml In RTF body

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00000142.bin rtf-objdata-decoded RTF \objdata at offset 0x142 2661 bytes
SHA-256: 71b961df6b4fe421d57077c0c294f992d62e2257acd15097f53278e230200796