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

Static analysis result for SHA-256 e51b9c6beaf87264…

MALICIOUS

Office (OLE) / .XLS

373.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: 0c10627bd2f63a71d0d2ccede5517f39 SHA-1: 5d9f08070a7381754f5fd65c1b539f427fdea851 SHA-256: e51b9c6beaf872642a0b433da61a653dc2a21c605d3a5fc937de0090b11fecde
160 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic for Applications T1204.002 Malicious File

The file is an Excel 4.0 spreadsheet containing an Auto_Open macro, which is a critical indicator of malicious intent. The macro uses dangerous functions like RUN, suggesting it's designed to execute arbitrary code. The presence of embedded URLs further supports the hypothesis that this macro acts as a downloader for a second-stage payload. The document body's content is minimal and appears to be obfuscated or corrupted, but the macro execution and embedded URLs are sufficient to infer the attack pattern.

Heuristics 5

  • 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
  • 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 https://techserve4u.com/utlqwePl9XKr/alex.html
    • https://evershinesoftware.com/isei5Q7KlsQ5/alex.html

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
599707db4356dee9b1659b3a18ea6968bd26a6e750ede458308d788c900c5e21
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 5292 bytes