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

Static analysis result for SHA-256 fda91092f89b0c0a…

MALICIOUS

Office (OLE) / .XLS

331.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: 3299b1a0715b986b6f9e366f31feb778 SHA-1: cc01f7f19c281bc536f78208bb11c1fbce9e1dd5 SHA-256: fda91092f89b0c0a29fee8ca67105864f7050bf9fe1ac50fa39fa7c0bc5e1b59
160 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic for Applications T1204.002 Malicious File T1059.001 PowerShell T1105 Ingress Tool Transfer

The file contains Excel 4.0 macros, specifically an Auto_Open function that utilizes dangerous APIs like RUN and CALL. This indicates an attempt to execute arbitrary code. The presence of an embedded URL suggests the macro's purpose is to download and execute a second-stage payload. The ClamAV detection name 'Doc.Downloader' further supports this conclusion.

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://zerones.biz/ds/261120.gif
    • https://zerones.biz/ds/261120.gif�

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
7fbdfe5319125c7a88728c7d99286583a9907fcc6c0161898412d727b081f128
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6676 bytes