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

Static analysis result for SHA-256 54761cf48b5bf6d5…

MALICIOUS

Office (OLE) / .XLS

31.0 KB Created: 2021-02-05 13:18:23 Authoring application: Microsoft Excel
MD5: a0721848f8dd048e811a9ec349347a9a SHA-1: 456a375f585af16c52121c7aad1b03a031143d3a SHA-256: 54761cf48b5bf6d5acaac5d0401aba9c84aee8dc46b29abbd7168c437ad6271f
160 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic for Applications T1204.002 Malicious File

The sample is an Excel 4.0 (XLM) macro-enabled spreadsheet. It contains an Auto_Open macro, which is a common technique for executing malicious code upon opening the document. The document body explicitly instructs the user to 'Enable Editing' and 'Enable Content', indicating a social engineering lure to bypass security measures. The XLM macro uses dangerous formula APIs, including the RUN function, suggesting it is designed 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
e1f2e81050d2269a5c5e162a29d97fa6dc3b09078ded5c46139f60c2cb0b1ead
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 3374 bytes