Android users, take note: There’s a malicious botnet currently in operation that could be using your device to send out bogus spam emails to thousands of unsuspecting individuals. The discovery was made by a Microsoft researcher who unearthed several “spam samples” that were coming from compromised Yahoo! accounts. What was particularly alarming about this discovery was the fact that the spam was originating from Android-powered gadgets.

The damning evidence, of course, was the “Sent from Yahoo! Mail on Android” line located at the bottom of these emails. Terry Zink, the man who first noticed botnet, said that questionable content was being sent from countries such as Chile, Indonesia, Lebanon, Oman, Philippines, Russia, Saudi Arabia, Thailand, Ukraine, and Venezuela, areas where cyber security isn’t as widely utilized.

Since Google Play has taken measures to ensure their downloads do not contain malicious software, Zink speculates users may have obtained the virus by downloading “free” versions of commercial software from third-party websites. The only alternative, according to this intrepid researcher, is that Android owners could have accidentally gotten their hands on a bogus Yahoo! Mail app somewhere down the line.

A representative from Google, meanwhile, was quick to comment on the security of their service, stating that, “Last year we also introduced a new service into Google Play that provides automated scanning for potentially malicious software without disrupting the user experience or requiring developers to go through an application approval process.”

For those who are still wondering what, precisely, a botnet is, here’s an explanation courtesy of Wikipedia:

A botnet is a collection of compromised computers, each known as a “bot”, connected to the Internet. Botnets are formed when computers are targeted by code within malware (malicious software). The controller of a botnet directs these compromised computers via standards-based network protocols such as IRC (Internet Relay Chat) and HTTP (Hypertext Transfer Protocol).

In short, it’s a network of computers used by hackers and nefarious types to send out emails and all sorts of nastiness. It’s not something you ever want to find yourself a part of. If you suspect that your Android device may, in fact, contain some malicious software, it’s suggested that you upgrade to the newest version of Android available.