Malicious Office (OLE) / .XLSX — malware analysis report

Static analysis result for SHA-256 f1a4a20953699eae…

MALICIOUS

Office (OLE) / .XLSX

1.30 MB
MD5: f98699b14920260d75462a9839615eee SHA-1: 4e4e2fd4ecf6d07f775f0bab453d13301f8a29ad SHA-256: f1a4a20953699eae11ba3258b1101a7b0e150be165ef0d0a157620a17ba924bb
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.001 Malicious Link: Malicious Link T1566 Phishing T1566.001 Phishing: Spearphishing Attachment T1059 Command and Scripting Interpreter

The file is an encrypted Office document that contains embedded OLE objects, specifically identified as leveraging the Equation Editor. This strongly suggests an exploit targeting a known vulnerability within the Equation Editor component to execute a payload. No scripts were extracted, but the presence of the Equation Editor OLE object is a high-confidence indicator of exploit delivery.

Heuristics 4

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Default-encrypted OOXML embedded OLE object xl/embeddings/oleObject1.bin contains the Equation Editor CLSID, the legacy component exploited by CVE-2017-11882, CVE-2018-0802, and CVE-2018-0798.
  • Default-encrypted OOXML exploit carrier layout high OOXML_ENCRYPTED_EXPLOIT_CARRIER_SHAPE
    Default-password encrypted OOXML package contains embedded OLE object parts and additional activation/decoy parts. This layout is common in malicious Excel exploit delivery and requires inspecting the decrypted package.
  • Equation Editor object carries payload-like Ole10Native stream high OLE_EQUATION_OLE10NATIVE_PAYLOAD_ANOMALY
    Default-encrypted OOXML embedded OLE object declares the Equation Editor CLSID but stores a large high-entropy Ole10Native stream with malformed package sizing. This is exploit-shaped Equation/OLE payload evidence.
  • Office OOXML encrypted with default VelvetSweatshop password medium OFFICE_DEFAULT_PASSWORD_ENCRYPTED_OOXML
    OLE EncryptedPackage decrypts with Excel's built-in VelvetSweatshop password. Office opens this transparently, and malware uses it to hide OOXML exploit parts from scanners that only inspect the outer OLE container.