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

Static analysis result for SHA-256 1525ad9cc1ded86b…

MALICIOUS

Office (OLE) / .XLSX

329.5 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: 385f6b0631f5ea86076da6e454dc05a5 SHA-1: 5675697e07428664701e0f7d809b49da6ed696fd SHA-256: 1525ad9cc1ded86b7afa251b57addb058d5e730e4bf361457406d515345b7c47
242 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros with an Auto_Open defined name, indicating an attempt to automatically execute code upon opening. The macro utilizes the RUN function, which is flagged as dangerous, and references ShellExecute API, suggesting it will download and execute a second-stage payload from the embedded URL http://ippp.co.zw/ds/161120.gif. ClamAV also detected this file as a downloader.

Heuristics 6

  • 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.
  • ClamAV: Doc.Downloader.Docusign0521-9864805-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Docusign0521-9864805-0
  • Reference to ShellExecute API high SC_STR_SHELLEXEC
    Reference to ShellExecute API
  • 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.
  • 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://ippp.co.zw/ds/161120.gif�

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
de64c8aedb9841e9622ce89b4c2a59532a2613bac9a0b05117fd5443ba276b2f
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 7888 bytes