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

Static analysis result for SHA-256 6f56693b3154f9ef…

MALICIOUS

Office (OLE) / .XLS

43.5 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: 9aa155010abd7e00ce0d0a7f4b8b2ac4 SHA-1: b8c1e2930b7fdec0b3488b819bc6febcef9f699c SHA-256: 6f56693b3154f9ef059aa6a5fd4e36ff78c1cd552c1f063726a0b7c307cd1ae6
180 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The file is an Excel 4.0 macro-enabled workbook containing an Auto_Open entry. Heuristics indicate the presence of dangerous formula APIs and an environment evasion halt gate within the macro. This suggests the macro is designed to execute commands, likely to download and run a second-stage payload, which is a common technique for malware delivery.

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
3761b3e6b17f30f9c35311b139b05534dda778fa6705a74bd116a97e1d63be16
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 12974 bytes