VBS/European-A worm file
File type: Dangerous and malicious file
Files with bll extension are known as dangerous email-aware files.
Found 3 different file type records with the same bll filename suffix.
File type category:
Dangerous and malicious file
Date updated: July 26, 2017
VBS/European-A is an email-aware Visual Basic Script worm. The worm creates a folder C:\startup, if it does not already exist, into which it copies itself with one of the following ten possible filenames:
"startup.bll"
"start.bll"
"winstart.bll"
"autoexec.bat.bll"
"win.ini.bll"
"config.bll"
"windoh.bll"
"fooled.bll"
"nothing.bll"
File type category:
Settings, options, themes or skins file
Date updated: September 23, 2026
The .bll file extension is associated with Borland Delphi, the Windows development environment from Borland. The file stores localization information used by the software.
A BLL file belongs to Delphi's supporting program files and is not Delphi source code or a project file. Its contents are intended to be read by Delphi when the corresponding localized resources are needed.
This is a legacy format associated with Borland-branded Delphi software for Microsoft Windows.
Open a BLL file through the Borland Delphi installation or the Delphi software that created it. It normally does not need to be opened separately.
A text editor or general-purpose file viewer is unlikely to display the file in a useful form, and editing it may prevent Delphi from using the localization data correctly.
A BLL file is not normally converted as a standalone file. Its localization information is intended for use by the associated Borland Delphi installation.
If localization must be changed, use the appropriate Delphi localization or resource workflow rather than trying to convert the BLL file with a general file converter.
Software apps that manage or store settings in bll files:
Microsoft Windows
File type category:
Various data file
Date updated: September 28, 2026
ENVI, developed by NV5 Geospatial, is remote-sensing and image-analysis software. An ENVI bad lines list records image line information for lines known to contain invalid or unreliable data.
The BLL file works with an associated raster dataset rather than storing image pixels itself. ENVI can use the list during image processing and analysis to account for the marked lines.
This is an ENVI-specific ancillary format intended for use with ENVI on Microsoft Windows, rather than a general-purpose image or data-exchange format.
Open the BLL file with ENVI on Microsoft Windows. In ENVI, load the associated raster dataset and use the software's bad-lines-list controls to select or import the file.
A BLL file is not an image and cannot normally be viewed meaningfully as a standalone picture; it must be interpreted together with the dataset for which it was created.
A BLL file normally has no useful standalone conversion because it contains ancillary line information rather than image data. To use the information elsewhere, recreate the bad-line list in the destination application using the line numbers stored in the file.
To modify the list for continued use in ENVI, edit or recreate it through ENVI's bad-lines-list tools rather than converting it to an image format.
Software applications that handle other tasks involving bll files:
Microsoft Windows
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