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

Static analysis result for SHA-256 a088982cdb014efb…

MALICIOUS

Office (OLE) / .XLS

253.0 KB Created: 2020-07-17 10:25:15 Authoring application: Microsoft Excel
MD5: 442508adf7e0ddc26b72f9858259b9aa SHA-1: e9c1beb8736869e023c9745d98ea547d05baf4df SHA-256: a088982cdb014efbf58a6b5b2df13ef43fefa6b595cb2ff5900da078cf3b70f4
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.001 PowerShell T1566.001 Spearphishing Attachment

The sample is an Excel file containing Excel 4.0 macros, specifically an Auto_Open macro. This macro is designed to execute arbitrary commands, indicated by the 'RUN=0' heuristic firing. The document body's instructions to 'Enable Editing' and 'Enable Content' are typical social engineering lures to trick users into activating macros. The presence of an Auto_Open macro strongly suggests the intent to download and execute a second-stage payload.

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
7136517e57e8f0ff4c6b873084c528c9bfd17f6eb216b1072b6161393f5f8fba
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 260386 bytes