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

Static analysis result for SHA-256 b19a6910112bdf7f…

MALICIOUS

Office (OLE) / .XLSX

1.14 MB
MD5: d4d69213a4488819ee33233d8af9ffc3 SHA-1: 8dbac65f1fe5843993353dbaece85ba8a37f7218 SHA-256: b19a6910112bdf7fcca247c7aaafa13504b410933dc858eeeec2557b5c4a9142
140 Risk Score

Malware Insights

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

The sample is an OOXML file that is encrypted with a default password and contains an Equation Editor OLE object. This object is known to be used as an exploit carrier, specifically for vulnerabilities like CVE-2017-11882. The 'OLE_EQUATION_OLE10NATIVE_PAYLOAD_ANOMALY' heuristic indicates that the Equation Editor object contains a payload-like stream, suggesting it's designed to execute malicious code. No specific family could be identified, but the delivery mechanism is clearly an exploit embedded within a document.

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.