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

Static analysis result for SHA-256 e58f730f799dd19b…

MALICIOUS

Office (OLE) / .XLSX

1.30 MB
MD5: fda3df9ca3f98fa73fd906900405e5bd SHA-1: 71cf8d326a64729ff9c11786a5892367e4236ea0 SHA-256: e58f730f799dd19b87e7f00d711ebe578293876e9a3cf770e40f410a534d3b5c
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1566 Phishing T1204.001 Malicious Link: Malicious File T1566.001 Phishing: Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is an encrypted OOXML file that contains embedded OLE objects, specifically identified as an Equation Editor exploit carrier. The presence of the Equation Editor OLE object and the anomaly in its Ole10Native stream indicate that it is designed to exploit a vulnerability, likely for client-side execution. The file is encrypted with a default password, a common tactic to evade initial static analysis.

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.