The Swiss bank PostFinance was hit by a distributed denial-of-service (DDoS) attack last night following its decision to freeze the defence fund and personal assets of WikiLeaks founder Julian Assange.

As revealed by SC Magazine yesterday, PayPal was hit by a DDoS after it ‘permanently restricted the account used by WikiLeaks due to a violation of its acceptable use policy'. The Anonymous group then instructed followers to hit PayPal, causing the site to be down for several hours.

Following the decision by PostFinance to freeze the finances of Assange, Anonymous announced via its Twitter feed that it was ‘preparing to attack again, this time with the help of the good people at WikiLeaks'. The bank's website appeared to be down for several hours and at the time of writing, was still down.

Sean-Paul Correll, threat researcher at Panda Security, said that the attack started at 8.30pm GMT and by 8.03am today, the attack on was still ongoing. However the attack is not just affecting the bank, with one Twitter user asking for the DDoS to be stopped so he could use the bank.

A report surfaced yesterday from CNET that claimed that MasterCard is also pulling the plug on payments to WikiLeaks, meaning that the only easy way to donate electronically would be with a Visa credit card through a web page hosted by Iceland-based

MasterCard spokesman Chris Monteiro, said: “MasterCard is taking action to ensure that WikiLeaks can no longer accept MasterCard-branded products. MasterCard rules prohibit customers from directly or indirectly engaging in or facilitating any action that is illegal.”

Meanwhile Assange turned himself into police in the UK following allegations of sexual assault this morning and is due to appear at Westminster Magistrate's Court later in the day. WikiLeaks spokesperson Kristinn Hrafnsson said that the arrest will not derail the release of more secret documents.