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

Static analysis result for SHA-256 4473634ddd0cd6c3…

MALICIOUS

Office (OLE) / .XLSX

1.35 MB
MD5: e4857ad9e70c4e50e4a315055340386b SHA-1: 32b0e71af46f3952561640ebe524b74dfb8ab3bf SHA-256: 4473634ddd0cd6c3af8780e384b2356c8526daf36a63ce80c949c88dcdace3a7
140 Risk Score

Malware Insights

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

The sample is an OOXML file that is encrypted with a default password and contains an Equation Editor OLE object. This strongly suggests it is designed to exploit a vulnerability within the Equation Editor component to execute arbitrary code. No specific family could be identified, and no direct IOCs like URLs or hashes were extracted from the static analysis.

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.