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

Static analysis result for SHA-256 aa786322b2bf68dc…

MALICIOUS

Office (OLE) / .XLSX

167.4 KB First seen: 2022-07-08
MD5: 2852499e1b48a6adcaf403b07eb0de56 SHA-1: 5c8b3c966cfd0a637e385f77d28d95dc9fc945e8 SHA-256: aa786322b2bf68dcfcc7160719527a98a2c80a6f82265600f5953337e6b2217d
202 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File T1059 Command and Scripting Interpreter T1059.001 Command and Scripting Interpreter: PowerShell

The sample is a password-encrypted OOXML document that exploits CVE-2017-0199. It contains an embedded OLE object that attempts to download a remote document from the URL http://www.w3schools.com@192.227.168.194/document/inv23/receipt.doc, likely to execute a second-stage payload. The document is malformed and encrypted, indicating a deliberate attempt to conceal its malicious nature.

Heuristics 6

  • OLE2Link / URL Moniker → remote loader — CVE-2017-0199 critical CVE likely CVE_2017_0199
    Document contains an embedded OLE link object whose URL Moniker points to a remote URL. When the host file is opened, Office follows the link, downloads the URL, and processes the response based on its Content-Type (HTA -> mshta.exe, RTF → Word, etc.) — the documented CVE-2017-0199 primitive. The URL extension is not a reliable filter; servers can return different payloads to Office's user agent.
  • Encrypted Office package with CFB FAT corruption critical OLE_ENCRYPTED_AND_MALFORMED
    Encrypted-package shape co-occurs with FAT-chain corruption — the documented combined evasion form.
  • 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.
  • Office document is password-encrypted medium OFFICE_ENCRYPTED_PACKAGE
    OLE container holds MS-OFFCRYPTO encrypted package (Standard Encryption (Office 2007, AES)).
  • 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.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://www.w3schools.com@192.227.168.194/document/inv23/receipt.doc