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

Static analysis result for SHA-256 563d7f43aa0efc1f…

MALICIOUS

Office (OLE) / .XLSX

1.42 MB
MD5: 13da804e33f75b4eece07454e7d6a46b SHA-1: 5aaccce2b706561af5d9ec7dcf946ee52a574720 SHA-256: 563d7f43aa0efc1f134f37d030e8d0318da17059fae91cc62b103aa5bb69bc9c
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious File T1204.002 Malicious File: Malicious Attachment T1559 Component Object Model Hijacking T1559.001 Component Object Model Hijacking: Component Object Model Hijacking

The sample is an OOXML file that is encrypted with a default password and contains an Equation Editor OLE object. This object exhibits an anomaly, indicating it carries a payload within its Ole10Native stream. This strongly suggests the file is designed to exploit a vulnerability in the Equation Editor to execute arbitrary code.

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.