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

Static analysis result for SHA-256 2c2a9f8994da6925…

MALICIOUS

Office (OLE) / .XLSX

1.38 MB
MD5: 680bd70bc57824293d9412570c4d513c SHA-1: 4b6d16747504e12cfee53ad1896b3f8ffd313490 SHA-256: 2c2a9f8994da69253ed12b7c7eb917b0509f8e3f78e0467768f1e66f262ae74e
140 Risk Score

Malware Insights

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

The sample is an encrypted OOXML file identified as an exploit carrier. It contains an Equation Editor OLE object, a common technique for delivering malicious payloads. The presence of an 'Ole10Native' stream within the Equation Editor object, with an anomalous size and entropy, strongly suggests it contains embedded malicious code. While no specific family is identified, this pattern is typical of macro-based malware 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.