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

Static analysis result for SHA-256 ce07dc9b67f4e91f…

MALICIOUS

Office (OLE) / .XLS

221.5 KB Created: 2021-02-06 22:23:31 Authoring application: Microsoft Excel
MD5: aeb9b7f6fb7bac0deac61db8295e1d3c SHA-1: 823814c91d8c75933f0f49cda5b07ac14e484390 SHA-256: ce07dc9b67f4e91fb0254421599c3344f60732b99c24d39d4f2a5b8e93da56ef
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File

The critical heuristics OLE_XLM_AUTOOPEN and OLE_XLM_DANGEROUS_FN indicate the presence of an Excel 4.0 macro designed to auto-execute. The extracted macro script reveals a formula that reconstructs and executes a PowerShell command. This command is designed to download a file from 'http://urgfuid.gq/z/z.exe', save it as 'z.exe' in the user's AppData directory, and then execute it, indicating a downloader or droppper functionality.

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
57c45528ba300fbb220b16b414386972502c3f4b2a8dc63ea50895b53e2a477d
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 1236 bytes