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

Static analysis result for SHA-256 3f311311fd6233ce…

MALICIOUS

Office (OLE) / .XLS

331.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: d85cdff747429b762c688dbaf61274a7 SHA-1: 760c5dcdee832d5573fdf630886cb7266d027bba SHA-256: 3f311311fd6233ce61a2700d5585e3bdafbf2c1148e279918956e33180491813
160 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open function that utilizes dangerous APIs like RUN. This indicates the macro is designed to execute arbitrary code. The heuristic firings and the presence of an embedded URL strongly suggest that this macro is intended to download and execute a second-stage payload from the provided URL. The ClamAV detection further supports its malicious nature as a downloader.

Heuristics 5

  • 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
  • XLM Auto_Open with dangerous formula APIs high 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.
  • 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://fu5on.com/ds/231120.gif
    • https://fu5on.com/ds/231120.gif�

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
fc23abdcb2657b335d0fb386451be5be98110592c06d0600d83d33c16e5bacb2
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6295 bytes