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

Static analysis result for SHA-256 6344bf2124713dac…

MALICIOUS

Office (OLE) / .XLS

94.5 KB Created: 2020-07-02 15:46:44 Authoring application: Microsoft Excel
MD5: ce1e562521007af6a0395b46eb974db9 SHA-1: afa76f6596ef0b23e760b53ba7121865617f52d9 SHA-256: 6344bf2124713dac7a4560e831d331d70662c4ae46666ffa20cc9a5376e53323
160 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 file containing Excel 4.0 macros, specifically an Auto_Open macro. Heuristics indicate the presence of a macro-enable lure and the use of dangerous formula APIs within the macro, suggesting it is designed to execute a payload. The macro itself is truncated, but the presence of Auto_Open and dangerous functions strongly implies it's intended to download and execute a second-stage payload.

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.
  • 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.
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
b3935a6eb326483d11ad133abfa68d78d8a2a806c3af34ab80678468752dba26
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 30998 bytes