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

Static analysis result for SHA-256 7a1e447f7534a388…

MALICIOUS

Office (OLE) / .XLSX

1.25 MB
MD5: 727cef81cf0948f6d8ed9a1308cf4ff0 SHA-1: 4f7c6fa08eba471217c7775f55e6d258cddbe2aa SHA-256: 7a1e447f7534a388da24abdb7187757d8db1402edc08b3d74bb763cd0a18f86e
140 Risk Score

Malware Insights

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

The file is an encrypted OOXML document, a common technique to evade initial detection. The presence of an Equation Editor OLE object within the spreadsheet is a strong indicator of malicious intent, as this is a frequent vector for delivering exploits. The OLE object contains a payload-like stream, suggesting it's designed to execute malicious code. The specific heuristics indicate the use of a known exploit carrier.

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.