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

Static analysis result for SHA-256 1e313eacb0f2334b…

MALICIOUS

Office (OLE) / .XLSX

1.16 MB
MD5: 912d5767c4e843b568aeb2e3706db74c SHA-1: 214d173969967b6a282f1c26523a9da449e1178d SHA-256: 1e313eacb0f2334b87804eb93042f03c62a41e908529e720cb77a294ce82cd90
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 Command and Scripting Interpreter T1071.001 Application Layer Compromise T1566.001 Privilege Escalation

The file utilizes a standard OOXML exploit delivery technique, embedding a malicious payload within a default-encrypted Excel package. The presence of the Equation Editor CLSID, coupled with the anomalous Ole10Native stream, strongly suggests an attempt to exploit CVE-2017-11882 or similar Equation Editor vulnerabilities. The decryption process reveals a hidden payload, likely designed to download and execute additional malicious code. The high heuristic scores further confirm this exploitation attempt.

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.