The Computer Incident Response Center Luxembourg (CIRCL) has issued advice to Dropbox users after data from 68 million accounts was leaked in August.

Among the information leaked were the usernames and passwords for 13,000 accounts registered to email addresses with Luxembourg domain suffixes.

CIRCL meanwhile says that many more Luxembourg residents could be concerned by the leak, as not everyone has an email address that ends “.lu”.

The theft from the American file hosting service was reported in 2012 by Dropbox, which then asked customers to change their passwords.

CIRCL reminds all Dropbox users who have not changed their passwords in the last few months to do so immediately.

If accounts are freely accessible, criminals may try to use this information for their own gain, it warns.

CIRCL reminds all internet users to select a strong password which is different for every kind of online service they use. In the case of the Dropbox leak, the passwords were encrypted but the response center warned passwords are easy to decrypt.