DESCRIPTION OF EVENTS
"For security reasons, addresses of online cryptocurrency wallets are composed of long strings of characters. Instead of typing them, users tend to copy and paste the addresses using the clipboard. A type of malware, known as a “clipper”, takes advantage of this. It intercepts the content of the clipboard and replaces it surreptitiously with what the attacker wants to subvert. In the case of a cryptocurrency transaction, the affected user might end up with the copied wallet address quietly switched to one belonging to the attacker."
"Although relatively new, cryptocurrency stealers that rely on altering the clipboard’s content can be considered established malware. ESET researchers even discovered one hosted on download.cnet.com, one of the most popular software-hosting sites in the world. In August 2018, the first Android clipper was discovered being sold on underground hacking forums and since then, this malware has been detected in several shady app stores." "Known as a “Clipper,” the malware replaces copied cryptocurrency wallet addresses with an address belonging to an attacker in the hope that funds will be sent elsewhere without the user noticing."
"The clipper we found lurking in the Google Play store, detected by ESET security solutions as Android/Clipper.C, impersonates a legitimate service called MetaMask. The malware’s primary purpose is to steal the victim’s credentials and private keys to gain control over the victim’s Ethereum funds. However, it can also replace a Bitcoin or Ethereum wallet address copied to the clipboard with one belonging to the attacker."
"This attack targets users who want to use the mobile version of the MetaMask service, which is designed to run Ethereum decentralized apps in a browser, without having to run a full Ethereum node. However, the service currently does not offer a mobile app – only add-ons for desktop browsers such as Chrome and Firefox."
"We spotted Android/Clipper.C shortly after it had been introduced at the official Android store, which was on February 1, 2019. We reported the discovery to the Google Play security team, who removed the app from the Store."
A fake MetaMask extension was found in the Google Play store. In addition to requesting and stealing the private keys of users, the malware is able to modify wallet addresses placed in the clipboard, tricking the user into sending funds to the attacker. It is unknown if there were any users losing funds as a result of the malware. There are no reports of any lost funds being recovered. The application has since been removed from the Google Play store.