Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 20503135d0b9b026…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:35:35 Authoring application: Microsoft Excel First seen: 2021-06-04
MD5: dd691ff97cd5c23a1730329508199bb3 SHA-1: 548d119305783e8935fa645c1cbe56695e389712 SHA-256: 20503135d0b9b0262fde1e63674e10fceb6e36890bba8a8d526c033d114804ab
140 Risk Score

Malware Insights

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

The sample is an Excel file containing Excel 4.0 macros, specifically an Auto_Open defined name, which is a critical finding. The presence of dangerous formula APIs like RUN indicates the macro is intended to execute external code. While no specific URLs or hashes were extracted, the macro's structure strongly suggests it acts as a downloader for 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) 6389 bytes
SHA-256: 5258971d9c17950da13a88bd63e797da426b77a4121de21df10b272edb11466b
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 -  esku
' 0018     25 LABEL : Cell Value, String Constant - AcclmqfnBl len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!F171 
' 0018     22 LABEL : Cell Value, String Constant - BEZfAHc len=0 
' 0018     22 LABEL : Cell Value, String Constant - Bpptdqo len=0 
' 0018     22 LABEL : Cell Value, String Constant - eXnqeka len=0 
' 0018     22 LABEL : Cell Value, String Constant - ExQaSih len=0 
' 0018     25 LABEL : Cell Value, String Constant - imRMnIGGcl len=0 
' 0018     20 LABEL : Cell Value, String Constant - JkIoS len=0 
' 0018     26 LABEL : Cell Value, String Constant - MhangdVpuEi len=0 
' 0018     24 LABEL : Cell Value, String Constant - MQdIktmZL len=0 
' 0018     24 LABEL : Cell Value, String Constant - nBoIGgrZj len=0 
' 0018     24 LABEL : Cell Value, String Constant - nQMTqmmfO len=0 
' 0018     23 LABEL : Cell Value, String Constant - poYIbGlG len=0 
' 0018     22 LABEL : Cell Value, String Constant - QZSgVbH len=0 
' 0018     21 LABEL : Cell Value, String Constant - uDXCNv len=0 
' 0018     22 LABEL : Cell Value, String Constant - uuBkrxJ len=0 
' 0018     25 LABEL : Cell Value, String Constant - VJfuUaRdAE len=0 
' 0018     26 LABEL : Cell Value, String Constant - xXEhhgSqoWG len=0 
' 0018     22 LABEL : Cell Value, String Constant - YYWtDgJ len=0 
' 0018     23 LABEL : Cell Value, String Constant - zioGwcaC len=0 
' 0018     25 LABEL : Cell Value, String Constant - ZjsUKAcVCd 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
' 00fd     10 LAB
... (truncated)

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