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

Static analysis result for SHA-256 5045e035f80ee203…

MALICIOUS

Office (OLE) / .XLS

136.5 KB Created: 2007-05-06 21:11:59 Authoring application: Microsoft Excel
MD5: 11c9ba362c344a164a06f7f91db73d55 SHA-1: 3c0d4af01d15feca9b2158e6f04fab88a10c3b96 SHA-256: 5045e035f80ee203236b9b34be5318029f1417ff765bc50124e43bfa02c5d37d
140 Risk Score

Malware Insights

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

The sample 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 document body displays a social engineering lure, instructing the user to 'Enable Editing' and 'Enable Content' to view the protected workbook, which is a typical phishing tactic. The Auto_Open macro likely executes dangerous functions, such as the RUN function, 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
591c7d96f99d4f2495940026c366e94af254650d5045b7b61e7a3379d555f7a5
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 80060 bytes