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

Static analysis result for SHA-256 0e7c1b885202e2e8…

MALICIOUS

Office (OLE) / .XLS

331.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: 9cc99ba86d2633b160f3f1302d254866 SHA-1: faec2e2c19119a62af2bc8371c56d36578a3c263 SHA-256: 0e7c1b885202e2e87d109d05d9a7abe1023832da6976026c80b5d3f141d9d93c
242 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution T1105 Ingress Tool Transfer

The file contains Excel 4.0 macros that are configured to automatically execute upon opening, as indicated by the Auto_Open defined name and the use of `RUN` and `CALL` functions. The macros construct strings that appear to be API calls and then execute them, likely to download and run a second-stage payload from the URL `https://tured.net/ds/261120.gif`. The ClamAV detection and heuristic firings confirm the malicious nature of this 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 https://tured.net/ds/261120.gif
    • https://tured.net/ds/261120.gif�

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
4805caad40efa88359221773489543a181039fb59e7111454d99230bce3bd306
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6674 bytes