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

Static analysis result for SHA-256 d952181645f30b1d…

MALICIOUS

Office (OLE) / .XLSX

1.21 MB
MD5: e82f66b3598492fdadf5b4f324501cf3 SHA-1: 109889f62e90ecb71472d113a5815af14f0ac7e5 SHA-256: d952181645f30b1da226e6cc83148cbe0bc9cdf6a11ae399af4a90dcd17d2f27
140 Risk Score

Malware Insights

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

The sample is an OOXML file encrypted with a default password, indicating a deliberate attempt to obscure its contents. It contains an Equation Editor OLE object, a common technique for delivering exploits. The anomaly in the Ole10Native stream suggests it carries a malicious payload, likely intended to be executed upon opening the embedded object.

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.