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

Static analysis result for SHA-256 ef17f47bcdb067d7…

MALICIOUS

Office (OLE) / .XLSX

1.18 MB
MD5: 7848697a2cff990710c69e8d97e55c13 SHA-1: 9af272f7dedd808c48b03d98d7eb75356b74f6ee SHA-256: ef17f47bcdb067d712661ddadff8ebee2924282c7fe21edd237e8094cc4ebdb0
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, indicating an attempt to obscure its contents. It contains embedded OLE objects, specifically identified as Equation Editor objects, which are frequently used to deliver exploits. The 'OLE_EQUATION_OLE10NATIVE_PAYLOAD_ANOMALY' heuristic suggests that one of these objects carries a payload within its Ole10Native stream, further supporting its role as an 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.