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

Static analysis result for SHA-256 8977149941a01de9…

MALICIOUS

Office (OLE) / .XLSX

138.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel First seen: 2022-07-13
MD5: a034bc54900af1487d792e7d0c4eb648 SHA-1: 1c76a97d4586e6ea62f242220bb544eb45be8844 SHA-256: 8977149941a01de9419af124115a4ec5df406c2b78b447ba52ed08cba766931b
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.005 Visual Basic T1203 Exploitation for Client Execution

The sample contains Excel 4.0 macros with an Auto_Open entry, indicating automatic execution upon opening. The document body and heuristics suggest a lure to enable macros, a common tactic for malware delivery. The macro is designed to download a second-stage payload from the URL http://nvelj12qyyfi03kqxy.xyz/i., which is a critical finding.

Heuristics 4

  • Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME
    oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
3a08691eed72e5ed205a0b2d682f61d57bf1de10bae67e5c55da30ecdcba1b08
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 4335 bytes