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

Static analysis result for SHA-256 8c7d8fc2a9743005…

MALICIOUS

Office (OLE) / .XLSX

1.55 MB
MD5: 0c44a9fa4ce2184c319d7d2b1dc6e319 SHA-1: fb24049452c8a31eab37ef00099b0604bd40cd95 SHA-256: 8c7d8fc2a97430056c231bcc2e3601fd27718e08c105171175789a6d86921cea
140 Risk Score

Malware Insights

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

The sample is an encrypted Office XLSX file. High-severity heuristics indicate it contains an Equation Editor OLE object, a common technique for delivering exploits. The OLE object's native stream appears anomalous, suggesting it carries a malicious payload. Due to the encryption and lack of document body, the specific exploit or payload could not be determined.

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.