Malicious RTF — malware analysis report

Static analysis result for SHA-256 84a4d2a64f2a3db1…

MALICIOUS

RTF

208.9 KB First seen: 2019-05-16
MD5: 3e7e46f8bf5fce6279ab1b6c51c4f71b SHA-1: 5b6c112238d7229b0b221d38e54722c5ceba992e SHA-256: 84a4d2a64f2a3db1d248e11b39cf14db4d78b66c1e8fb6b86460a6cba7aaa380
140 Risk Score

Malware Insights

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

The RTF file contains an embedded OLE object that is configured to automatically activate and load a remote resource. This is indicative of exploitation for client execution, likely delivered via a spearphishing attachment. The specific vulnerabilities targeted are CVE-2017-0199 and CVE-2017-8759, which allow for the execution of arbitrary code by loading a remote moniker.

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_off0000003b.bin rtf-objdata-decoded RTF \objdata at offset 0x3B 2605 bytes
SHA-256: 3c4b31624b2dc083125702d0df9de32a5285dae6fb56fb2bedd8ecf165b19ff4