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

Static analysis result for SHA-256 1e7447cb7adb3336…

MALICIOUS

Office (OLE) / .XLSX

1.21 MB
MD5: b7cdda847140697b7bb7866b06d2a225 SHA-1: 874d1157c6e65813383c6b4bffd4d48948993c88 SHA-256: 1e7447cb7adb3336fcf6d2837781a2ab0d9f9fd3060cde3a47293bd34a883cdb
140 Risk Score

Malware Insights

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

The sample is an OOXML file encrypted with a default password, a common technique to evade initial static analysis. It contains embedded OLE objects, specifically identified as Equation Editor objects, which are frequently used to deliver exploits. The anomaly in the Ole10Native stream size suggests it's designed to carry a malicious payload, likely exploiting vulnerabilities within the Equation Editor component.

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.