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

Static analysis result for SHA-256 6af62a337c410357…

MALICIOUS

Office (OLE) / .XLSX

1.11 MB
MD5: ab57abd998267541ce6d27ecf2b85ba5 SHA-1: 4840478268380cf80e55d5ca019d108236d100a6 SHA-256: 6af62a337c410357a5f49294e98ead83092c6a1d3b73e58c2f56ea5abfdd745e
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file is an encrypted OOXML document, identified as an exploit carrier due to the presence of an Equation Editor OLE object. This object contains an anomalous Ole10Native stream, strongly suggesting it is used to deliver a malicious payload. The default password encryption further supports its malicious intent, as it's a common technique to evade initial static analysis.

Heuristics 5

  • 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 document is password-encrypted medium OFFICE_ENCRYPTED_PACKAGE
    OLE container holds MS-OFFCRYPTO encrypted package (Standard Encryption (Office 2007+, AES-128)).
  • 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.