Windows

$Recycle.bin and System Volume Information" folders

Estas carpetas son creadas por Windows en todas las particiones; incluyendo disco duros externos. No son virus.

Both of them are safe.

https://www.quora.com/Are-Recycle-bin-and-System-Volume-Information-folders-viruses-in-Windows-8-OS

$Recycle.bin is the folder that contains the files which you deleted on that drive. It acts as a Recycle bin folder.

Containing folders for each SID(Security ID for each User) and the Recycle bin.

About System Volume Info :

The folder contains information that casual interference could cause problems with proper system functioning. Here are some of the things kept in that folder. (This list is not comprehensive.)

• System Restore points. You can disable System Restore from the "System" control panel.
• Distributed Link Tracking Service databases for repairing your shortcuts and linked documents.
• Content Indexing Service databases for fast file searches. This is also the source of the cidaemon.exe process: That is the content indexer itself, busy scanning your files and building its database so you can search for them quickly. (If you created a lot of data in a short time, the content indexer service gets all excited trying to index it.). Cidaemon might be Search Indexer in windows 7.
• Information used by the Volume Snapshot Service (also known as "Volume Shadow Copy") so you can back up files on a live system.

Source: MSDN Blog Archive.