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

Static analysis result for SHA-256 339c8dadf233a394…

MALICIOUS

Office (OLE) / .XLSX

1.23 MB
MD5: c2b1685b5e9b13acce9943d22088082b SHA-1: 106ed53e2f9c273a7bba8adc0efc5993af07acfb SHA-256: 339c8dadf233a39452a1cc590962ec52df9bff9e19e8697d78c98afd510d206f
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1559.001 Component Object Model Hijacking

The sample is an encrypted OOXML file that utilizes default password encryption, a common technique for obfuscating malicious content. High-severity heuristics indicate the presence of an Equation Editor OLE object, which is known to be exploited via CVE-2017-11882. This object contains an anomalous Ole10Native stream, suggesting it carries a payload. The embedded OLE objects are indicative of an exploit carrier designed to leverage the Equation Editor vulnerability to compromise the user's system.

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.