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

Static analysis result for SHA-256 4fdcc17087f3090f…

MALICIOUS

Office (OLE) / .XLSX

1.28 MB
MD5: 50d4e7b254ae9bcbcc7576db489a6d94 SHA-1: 1b0115b325d34a22ac1d10810b4d96720616c38e SHA-256: 4fdcc17087f3090f083e20e78cc551133f031dfa04a220532adffeaa4eb92942
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File T1559 Component Object Model Hijacking T1559.001 Component Object Model Hijacking: Component Object Model Hijacking

The sample is an OOXML file encrypted with a default password, indicating it's designed to hide its malicious content. High-severity heuristics indicate the presence of an Equation Editor OLE object, which is a known carrier for exploits. This object contains an anomalous Ole10Native stream, strongly suggesting it's used to deliver a second-stage payload.

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.