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

Static analysis result for SHA-256 44970b2253206166…

MALICIOUS

Office (OLE) / .XLSX

1.16 MB
MD5: 7bd8488e318fb294a56ba2057d3eb203 SHA-1: 736e2eaa936aa29697426204f64c8f1ed98e6926 SHA-256: 44970b225320616624ad0c5e4828bc1b333b049496120fc0412f92fd0c927ddb
140 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The OOXML document is encrypted with a default password and contains an embedded Equation Editor OLE object, which is a known exploit carrier. The Equation Editor object exhibits anomalies suggesting it carries a payload, likely exploiting a vulnerability such as CVE-2017-11882. This indicates the file is designed to deliver a secondary malicious payload upon opening.

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.