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

Static analysis result for SHA-256 c0dea9678b4b59aa…

MALICIOUS

Office (OLE) / .XLS

76.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-05-24
MD5: 283ead9a3b29980b8cc5494ae86d3264 SHA-1: 02cb9a572ae67493ab863d0ebf676564e7549766 SHA-256: c0dea9678b4b59aab273d11d7c2c35b66e89d9760b1772485863be4823315e7d
140 Risk Score

Malware Insights

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

The critical heuristics indicate the presence of Excel 4.0 macros with an Auto_Open function that calls dangerous APIs, specifically the RUN function. This strongly suggests the macro is designed to execute arbitrary commands. The extracted URLs are likely used to download and execute a second-stage payload. The confidence is high due to the direct indicators of macro execution and the presence of download URLs.

Heuristics 3

  • 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.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
1253b9aedc963f347f6b0e8960abed4c25ca841ad10b30851eba81a4b10acde3
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 7159 bytes