Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 3e35a7d4ebfc15ba…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:38:44 Authoring application: Microsoft Excel First seen: 2021-09-24
MD5: b5214510d61bca1266276b82c496b06a SHA-1: c8de5a13da4f3ccb6455c12b2f2cf265d4e878c3 SHA-256: 3e35a7d4ebfc15baa524a7a058ec13e9a759ffdab8919343a15e824d48f46122
140 Risk Score

Malware Insights

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

The file is an Excel 4.0 macro-enabled workbook detected with critical heuristics for Auto_Open functionality and the use of dangerous formula APIs. The Auto_Open macro is designed to execute arbitrary code, which is a common technique for downloading and executing further malicious payloads. No specific family could be identified from the available evidence.

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) 6623 bytes
SHA-256: 7e61b6ae8f880db52b3896e196e8c66aa5676a80d7d7a5e3e172d9249512433a
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     17 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  hiwYBnhC
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!C156 
' 0018     26 LABEL : Cell Value, String Constant - fdnvIwSgzuH len=0 
' 0018     24 LABEL : Cell Value, String Constant - GsSuBMNBR len=0 
' 0018     24 LABEL : Cell Value, String Constant - gXHogLUgh len=0 
' 0018     26 LABEL : Cell Value, String Constant - HphlkDGtsDE len=0 
' 0018     22 LABEL : Cell Value, String Constant - hxEKNRA len=0 
' 0018     25 LABEL : Cell Value, String Constant - JALStpJcdj len=0 
' 0018     20 LABEL : Cell Value, String Constant - jUlnL len=0 
' 0018     26 LABEL : Cell Value, String Constant - kerxLNmKmoI len=0 
' 0018     23 LABEL : Cell Value, String Constant - KYBxHsFv len=0 
' 0018     23 LABEL : Cell Value, String Constant - mspnLfEw len=0 
' 0018     21 LABEL : Cell Value, String Constant - nQFGPx len=0 
' 0018     26 LABEL : Cell Value, String Constant - OGOJDpYEeyA len=0 
' 0018     21 LABEL : Cell Value, String Constant - QCZWFf len=0 
' 0018     24 LABEL : Cell Value, String Constant - sUROsPuoB len=0 
' 0018     26 LABEL : Cell Value, String Constant - vvnzNyfLPnK len=0 
' 0018     26 LABEL : Cell Value, String Constant - WyNXMOZFCEa len=0 
' 0018     22 LABEL : Cell Value, String Constant - xUTVWJp len=0 
' 0018     24 LABEL : Cell Value, String Constant - YFwzSGopo len=0 
' 0018     26 LABEL : Cell Value, String Constant - yRbOcFVuHZJ len=0 
' 0018     22 LABEL : Cell Value, String Constant - ZNNKWid 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)

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