One of the most popular Bitcoin wallets, Electrum, has been hit by a denial-of-service, the company announced on Twitter. Electrum said its developers were already working on a more secure version of the wallet, and asked its users to disable auto-connect and select their server manually.
The attack was carried out by a very powerful botnet, which had affected 140,000 machines and directed unsuspecting users to a version of the Electrum software that had been hacked and was stealing their digital currencies.
The attackers appear to have primarily targeted users running older versions of the software, where the automatic login option was still available. Users are advised to update their software manually immediately.
Electrum developers are already working to resolve the issue, however it is possible that users may experience service interruptions.
While the motives behind this attack are unclear, Electrum's lead developer, Thomas Voegtlin, believes it is a counterattack. Electrum had previously been phished by a Trojan known as Electrum Stealer. Electrum developers modified some servers to increase protection against such an attack. This is the gap that the attackers have exploited.
Voegtlin said: “We are not sure what motivates the attackers. It could be some kind of counterattack after the steps we took last month to prevent phishing attacks.”
He also advised Electrum users to download the Electrum software exclusively from the Electrum.org website. They can also use the official GitHub wallet depository. This is the only way to protect themselves from the attack.
