[RCU] Sqlite db problem

Hello Everyone,

Today I faced strange thing. I am monitoring my server with AIDE software. It detects changes in the filesystem structure, for example notifying me about file being created, changed or deleted. What I spotted was that sqlite.db file was created in my roundcube/bin directory. What's more when I check original location of the file which is roundcube/sqlite.db it was 11G in size! Is this normal? What is exactly stored in the file? I removed (previously backed up) both files and everything seems to be working OK. So I am wondering - did someone "visited" my server and did something nasty? Or is this suppose to happen and sqlite.db can grow to 11G over time?

Any help would be greatly appreciated. Thanks!