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

Static analysis result for SHA-256 c5a7c8cd2cb80268…

MALICIOUS

Office (OLE) / .XLSX

45.0 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: 378df42df361ab47525171fa2264721f SHA-1: a2e1b9f9cc3bde43b1e7d08880cde381ff34c23d SHA-256: c5a7c8cd2cb80268ee70e781bf2e1688b03ad75b8b13df18e64434960bc3a5ac
180 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open function, which is a known method for executing malicious code. The heuristics indicate the presence of dangerous formula APIs and an environment-evasion halt gate, suggesting an attempt to run arbitrary commands. The extensive obfuscated text in the document body further supports a malicious intent, likely to deceive the user into enabling macros or to perform further malicious actions upon opening.

Heuristics 4

  • 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.
  • XLM Auto_Open environment-evasion HALT gate high OLE_XLM_ENVIRONMENT_EVASION_HALT
    Excel 4.0 macro sheet auto-executes multiple GET.WORKSPACE / GET.WINDOW environment checks and halts execution when the host does not match the expected user environment. This is a common sandbox-evasion pattern in XLM malware and is stronger than a bare XLM macro-sheet indicator.
  • 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
f3e749c00d954fc92a48830ee3fc33f3a8a7e6b9d182eb177904b2db77a5054c		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 14049 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.