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

Static analysis result for SHA-256 ccc279d0c94f49b5…

MALICIOUS

Office (OLE) / .XLSX

2.28 MB
MD5: 4849b57f8d4620e562dee531d6dada3f SHA-1: 187d46376416218f77e7330da4f1576dd135d394 SHA-256: ccc279d0c94f49b5594dd87ca63a6de0b94f29e389db2d04a396eefa81820b29
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 the presence of an Equation Editor OLE object, a common technique for delivering exploits. The object contains a payload-like stream with an anomalous header, suggesting it's designed to execute malicious code. No document body or scripts were extractable due to encryption, but the OLE object's structure strongly implies an exploit delivery mechanism.

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.