Malicious RTF — malware analysis report

Static analysis result for SHA-256 c84faff850e4f48a…

MALICIOUS

RTF

341.1 KB First seen: 2021-09-24
MD5: 04f478a39f1108b7695249174a3ea74f SHA-1: 26f050424a5f5642c204f44c776f32023b464be3 SHA-256: c84faff850e4f48a04dc103bd45aa59fc5d85a4214017f05eeac2ecf4c14861d
240 Risk Score

Malware Insights

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

This RTF document was flagged as malicious. It uses an "enable content/editing" lure. Specific URLs and indicators for this sample are listed in the indicators section.

Heuristics 7

  • Composite Moniker — CVE-2017-8570 (drops SCT script) critical CVE related CVE_2017_8570
    RTF \objdata decodes to OLE data containing the Composite Moniker — CVE-2017-8570 (drops SCT script) CLSID — the vulnerable control/moniker is embedded directly in the document's object stream, the delivery shape of this exploit. RTF objects auto-render when Word opens the file.
  • Composite Moniker in RTF OLE object high CVE related RTF_COMPOSITE_MONIKER_RELATED
    RTF contains Composite Moniker CLSID in OLE object context, but no nearby scriptlet/SCT payload was confirmed. Treat as related moniker attack-surface evidence rather than proof of CVE-2017-8570 exploitation.
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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 3 \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

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00000969.bin rtf-objdata-decoded RTF \objdata at offset 0x969 75688 bytes
SHA-256: d75584863ead3412eaf80d0184b2578cca179218233c606ef2981ea0f8873c76
objdata_01_off00027100.bin rtf-objdata-decoded RTF \objdata at offset 0x27100 2632 bytes
SHA-256: 10a6f8600e8524cd28573939a4ae1bdfdf968f5507d04011336569618d3ad498
objdata_02_off000286a3.bin rtf-objdata-decoded RTF \objdata at offset 0x286A3 12297 bytes
SHA-256: 44deae4627fee3c44f54d5bd10477ec2e17f4c08135f08e2417832e36d10d037