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

Static analysis result for SHA-256 e70ad1f7b0018147…

MALICIOUS

Office (OLE) / .XLS

53.0 KB Created: 2020-10-23 10:21:20 Authoring application: Microsoft Excel
MD5: fa8051a79f6b01a8ffa48aa9399741af SHA-1: 36ae4e043f0d8c3f5840125c0f581f082feb938d SHA-256: e70ad1f7b001814750fa1d74208cf69027b3be0c68e13c01cfd30c34929af4c5
180 Risk Score

Malware Insights

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

This Excel 4.0 macro-enabled document contains an Auto_Open defined name, indicating it will execute macros upon opening. The presence of dangerous formula APIs like RUN suggests the macro is designed to execute arbitrary code. Additionally, environment evasion techniques were detected, commonly used to hinder analysis. The macro likely downloads and executes a second-stage payload, a common tactic for initial access.

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
4e6b9f65a36f4e9b1af0ca7ba8f8cff545567d9556dcaad10d0ce290afc4f4f3		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 16034 bytes

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