An Garda Siochana is a scam that targets many computers today, primarily located in Ireland and in some other neighboring countries. Great Britain, by the way, is also attacked by this virus massively, in addition to the PCEU (Metropolitan Police) virus locker. This scam belongs to the ransomware category, i.e. this is the malware that blocks the desktop of the target computer with the scary police warning. In this particular case, the scary warning is allegedly coming from the Ireland’s National Police Service (which is called An Garda Siochana, by the way). The truth, however, is that this warning that you see depicted below has nothing to do with the Irish police, so you should be careful not to trust any deceitful statement contained in this virus that locked your system.