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

Static analysis result for SHA-256 30b7915569dba9d1…

MALICIOUS

Office (OLE) / .XLSX

1.16 MB
MD5: 5233627de3c47be2156f99cc68720377 SHA-1: fcc19db31d01aac0d32e7630e401fab2e48dab13 SHA-256: 30b7915569dba9d1a98a25fade75997c07558cfb5f7fd5e23fdc8945ddf22e50
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1566 Phishing T1204.001 Malicious Link: Malicious File T1566.001 Phishing: Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is an OOXML file encrypted with a default password, indicating it's designed to hide its malicious contents. High-severity heuristics indicate the presence of an Equation Editor OLE object, which is a known carrier for exploits. This object contains a payload-like stream, suggesting it's intended to execute code upon opening. The combination of these factors points to a likely exploit delivery mechanism.

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.