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

Static analysis result for SHA-256 628562c5bcff5846…

MALICIOUS

Office (OLE) / .XLS

142.0 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: 5d14a45e047395fe05c72d554a984c44 SHA-1: ca9c81c059233c54789d712f8f22e3b57796d103 SHA-256: 628562c5bcff5846ea619697f08159d8e3241e76877b191b6d8c8c505677bdf9
180 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.005 Visual Basic T1203 Exploitation for Client Execution

The sample is an Excel 4.0 (XLM) macro-enabled workbook. It contains an Auto_Open macro that attempts to evade detection and execute dangerous functions. The document body claims the file is encrypted and prompts the user to enable editing, a common lure for macro execution.

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
eadc177373e0f1f3994095a6fe983ebd892fd3b68aba4a6cc1871417b9a64111
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 168484 bytes