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

Static analysis result for SHA-256 d692fafc062c8333…

MALICIOUS

Office (OLE) / .XLSX

1.16 MB
MD5: 6007ed74231a586d761cd259eeec19f5 SHA-1: a77b046b3a56044b09f310ffd4c33107ed6b0217 SHA-256: d692fafc062c83334de86872be91815c4c5f2711df9e81a97519544a008fe6e4
140 Risk Score

Malware Insights

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

The sample is an encrypted Office XLSX file that contains embedded OLE objects, specifically identified as Equation Editor objects. These objects are known exploit carriers, and the presence of an 'Ole10Native' stream within the Equation Editor object suggests it's designed to deliver a payload. The high entropy of the stream further supports this. The encryption with a default password and the nature of the embedded object point towards a malicious document designed to exploit vulnerabilities upon opening.

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.