One of the most popular Bitcoin Wallets, Electrum, was the victim of an attack denial-of-Service, according to the company's announcement via Twitter. Electrum said its developers were already working on creating a safer version of the e-wallet, and asked its users to disable auto-connect and choose 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 Electrum software that had been tampered with and stole their digital coins.
Attackers seem to have focused primarily on users using old versions of the software, where there was still an automatic connection option. It is recommended that users instantly update their software manually.
Electrum developers are already working to solve the problem, but users are likely to experience service interruptions.
While the motivation behind this attack is unclear, Electrum chief programmer, Thomas Voegtlin, thinks this is a counterattack. Electrum had previously been cheated by phishing from a Trojan known as Electrum Stealer. Electrum developers have modified some servers to increase protection from such an attack. This is the gap that the attackers have taken advantage of.
Voegtlin said: "We are not sure what motivates the attackers. It could be a kind of counterattack following the steps we took last month to prevent phishing attacks. "
He also advised Electrum users to download Electrum software exclusively from Electrum.org's website. They can also use the official GitHub wallet depository. This is the only way to protect themselves from the attack.