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

Static analysis result for SHA-256 4e7fd05e0ea98e3f…

MALICIOUS

Office (OLE) / .XLS

36.0 KB Created: 2020-11-25 10:40:50 Authoring application: Microsoft Excel First seen: 2022-04-27
MD5: 171b0ca8c75328185e8c7849278df693 SHA-1: 9874fdd59f3c0d6695cbd7a6fd9d477d147db62b SHA-256: 4e7fd05e0ea98e3f1ab4d5fa195c8dd5f3a36adf7d98581a4e0691f97b64ee38
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Service Execution: Visual Basic T1059.001 Command and Scripting Interpreter: PowerShell T1204.002 Malicious File Execution: Malicious File

The file is an Excel 4.0 (XLM) macro-enabled spreadsheet. Heuristics indicate the presence of an Auto_Open macro, which is a common technique for executing malicious code upon opening the document. The macro sheet contains calls to dangerous functions, including 'RUN', suggesting it is designed to execute arbitrary commands or download and run a second-stage payload. No specific family could be identified, but the technique is consistent with macro-based malware delivery.

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
a62c8a7cc8a70c10af2652029e45564dc1d90692e34066ab886a9ed06c73d7ff
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6654 bytes