Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 20b012cfc545920b…

MALICIOUS

Office (OLE)

35.5 KB Created: 2020-11-25 10:45:22 Authoring application: Microsoft Excel First seen: 2021-06-13
MD5: 808efcb785557faca4a563db177b3be9 SHA-1: d3a90c946a05b993b0a902e79389ecb9849f48c8 SHA-256: 20b012cfc545920b811f3d3789003e871764154038324a3bb6d3b02048afb8e2
140 Risk Score

Malware Insights

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

The file is an Excel document containing Excel 4.0 macros, specifically an Auto_Open function. This function is designed to execute automatically when the workbook is opened, indicating an attempt to run malicious code. The presence of dangerous formula APIs within the macro further supports this. The likely intent is to download and execute a second-stage payload.

Heuristics 3

  • 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.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6450 bytes
SHA-256: df5f4db44e559e96052bb016d50f48dfcb62bb07b1de600e83b317e0083ee519
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     13 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  kyWF
' 0018     23 LABEL : Cell Value, String Constant - asoNDvnD len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!A152 
' 0018     25 LABEL : Cell Value, String Constant - BYHKUaJYlH len=0 
' 0018     20 LABEL : Cell Value, String Constant - EFAom len=0 
' 0018     27 LABEL : Cell Value, String Constant - fWwYGJpzDTFT len=0 
' 0018     20 LABEL : Cell Value, String Constant - hKmOY len=0 
' 0018     21 LABEL : Cell Value, String Constant - iwNJYl len=0 
' 0018     27 LABEL : Cell Value, String Constant - KMKiXLxSNEEu len=0 
' 0018     25 LABEL : Cell Value, String Constant - kpOCHgtZqf len=0 
' 0018     27 LABEL : Cell Value, String Constant - mnsoBtHvPunX len=0 
' 0018     25 LABEL : Cell Value, String Constant - narDpEJtFQ len=0 
' 0018     23 LABEL : Cell Value, String Constant - NyMiVnfC len=0 
' 0018     27 LABEL : Cell Value, String Constant - OgHhVqIMPRqr len=0 
' 0018     23 LABEL : Cell Value, String Constant - rIsZPdNl len=0 
' 0018     26 LABEL : Cell Value, String Constant - rVtDoinKXPY len=0 
' 0018     24 LABEL : Cell Value, String Constant - SWxTsDCEk len=0 
' 0018     26 LABEL : Cell Value, String Constant - TURuVIqErev len=0 
' 0018     24 LABEL : Cell Value, String Constant - uenuIzTbn len=0 
' 0018     27 LABEL : Cell Value, String Constant - yTfVTqJLToOI len=0 
' 0018     20 LABEL : Cell Value, String Constant - ZhCDU len=0 
' 0018     22 LABEL : Cell Value, String Constant - ZuFlZAy len=0 
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST

... (truncated)

Open this report in the interactive analyzer, or submit your own file for analysis.