A bit of a warning, if you have download CCleaner recently, their installer was infected with malicious software. With millions of downloads last month the end-users may have been infected.

Talos, a branch of security company Cisco made the discovery, hackers have been able to inject malware as they hacked into the British company Piriform, who develops CCleaner. CCleaner is free software that can improve the performance of a computer. According to researchers, the program is downloaded five million times a week for PCs and Android phones.

The infected version of CCleaner could be downloaded in August, the exploit services tried to connect to several unregistered websites, possibly to download more malware. Reuters reports that researcher Craig Williams states that the malware spreads in a similar manner to the NotPetya attack in June. That malware was spread through infected Ukrainian accounting software.

CCleaner makes use of a digital certificate which allows computers to automatically trust the program during installation. Piriform recommends users of CCleaner version 5.33.6162 and CCleaner Cloud version 1.07.3191 to download new versions of the software. The program is not updated automatically.

Popular software CCleaner infected with backdoor