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

Static analysis result for SHA-256 fb94e0bd93b98047…

MALICIOUS

Office (OLE) / .XLS

71.0 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-06-08
MD5: 2f85bf493217c29023600ac7db9de575 SHA-1: db91219bcbf8fb76fe5ddf0059f6ed4f4010a8c2 SHA-256: fb94e0bd93b98047396983324c296ff55798d35cfc7ba22232d50f7166113bb5
140 Risk Score

Malware Insights

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

The critical heuristics indicate the presence of Excel 4.0 macros with an Auto_Open entry point, which is a known method for executing malicious code. The macro sheet contains formulas that call dangerous functions, including RUN, suggesting it attempts to download and execute a second-stage payload from one of the provided URLs. The extracted URLs are highly suspicious and likely serve as the distribution points for the malware.

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
5111faade6798439ce43161a25c95a0c795073df8f05008e90c40cef2fd124d6
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 7798 bytes