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

Static analysis result for SHA-256 4a57700901dde033…

MALICIOUS

Office (OLE) / .XLSX

1.13 MB
MD5: fde8f326ad2776b9b9e9976a9075fdcf SHA-1: f815ea2723f77337685ae15c72815a02d638732c SHA-256: 4a57700901dde03320e1f9b84aa93f4f4e309c46f18fb6c686fe69be4253df4b
100 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 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, which is a common vector for exploiting vulnerabilities like CVE-2017-11882. The encryption with a default password further suggests malicious intent, preventing easy inspection of its contents.

Heuristics 3

  • 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.
  • 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.