Malicious RTF — malware analysis report

Static analysis result for SHA-256 a7cf17bda899b3ba…

MALICIOUS

RTF

949.5 KB Created: 2019-09-17 13:59:00 First seen: 2020-07-02
MD5: 528289495d7379fb5dcd40ba67e0f77d SHA-1: 461711d8e8f7e75eb1a5f1304b71e1585bea1693 SHA-256: a7cf17bda899b3ba3d93a4190e003dfceabc0cd5bfa3f09200346c0b265820c8
142 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 forced to activate via \objupdate, triggering the CVE-2017-8759 vulnerability. This exploit is commonly used to download and execute a second-stage payload. The presence of the benign URL is not considered a primary IOC.

Heuristics 5

  • CVE-2017-8759 — MSXML SAX OLE activation critical CVE likely CVE_2017_8759
    RTF contains a hex-encoded OLE1 object for Msxml2.SAXXMLReader.6.0 followed by an embedded OLE compound document, and the document requests OLE activation. This matches the RTF staging shape used for CVE-2017-8759 SOAP/WSDL parser code injection.
  • \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
  • 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_off000e843d.bin rtf-objdata-decoded RTF \objdata at offset 0xE843D 1414 bytes
SHA-256: 2c908dd6d411040e6def6d6d16bc16f913f641cbcc4cf668a09b32dfbbbd64a7