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

Static analysis result for SHA-256 b17b9942c16dca4e…

MALICIOUS

Office (OLE) / .XLSX

1.31 MB
MD5: d8bde6bc190a6d9af06410f07cd347d4 SHA-1: ab4ac9280eeb7bf9eb81f6d1306138b614274f40 SHA-256: b17b9942c16dca4e99e6598e31255bc11d36a85ae0c7aad08f43b304c48ebb39
140 Risk Score

Malware Insights

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

The OOXML file is encrypted with a default password and contains an Equation Editor OLE object. This is a common technique for delivering exploits, specifically targeting vulnerabilities within the Equation Editor component. The presence of 'oleObject1.bin' and 'oleObject2.bin' further indicates a complex embedded structure likely designed to conceal malicious content. The high entropy of the Ole10Native stream suggests it contains packed or encrypted shellcode.

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.