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

Static analysis result for SHA-256 db12524b47193775…

MALICIOUS

Office (OLE) / .XLSX

1.29 MB
MD5: ee93a692c31033de3fedd144b1153d3d SHA-1: 651a711830e674c2d69a19a95beb43172aab45f3 SHA-256: db12524b47193775807b6650b9516504d23716618b7f406cd2b98b213d79c6ce
140 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 Malicious Link

The sample is an encrypted OOXML file that contains an Equation Editor OLE object. This object carries a payload-like Ole10Native stream, indicating it's likely used to exploit a known vulnerability in the Equation Editor component. The encryption and the presence of the Equation Editor exploit carrier strongly suggest a malicious intent to deliver a secondary 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.