Suspected Mariposa botnet mastermind is denied bail

IserdoThe man believed to have created the Mariposa botnet which compromised millions of computers across the globe, has been denied bail.

Matjaž Škorjanc, believed by the authorities to be the hacker known as “Iserdo”, was arrested in the city of Maribor, Slovenia, back in 2010.

The Mariposa botnet was brought down at the end of 2009, but at its peak, the botnet (named after the Spanish word for “butterfly”) had hijacked almost 13 million computers in more than 190 countries.

The PCs had been silently commandeered by hackers after being infected by the polymorphic Rimecud family of malware, which spread via a variety of methods including removable storage devices, instant messaging and P2P file-sharing systems.

Sign up to our free newsletter.
Security news, advice, and tips.

Once a computer had been compromised and brought into the botnet, operators could steal information from innocent users – including their credit card details and banking passwords.

According to the authorities, the Mariposa botnet’s code was sold to hundreds of online criminals around the world.

Matjaž Škorjanc was denied bail of 61,000 Euros, and his trial will resume in May.


Graham Cluley is an award-winning keynote speaker who has given presentations around the world about cybersecurity, hackers, and online privacy. A veteran of the computer security industry since the early 1990s, he wrote the first ever version of Dr Solomon's Anti-Virus Toolkit for Windows, makes regular media appearances, and is the co-host of the popular "Smashing Security" podcast. Follow him on Twitter, Mastodon, Threads, Bluesky, or drop him an email.

2 comments on “Suspected Mariposa botnet mastermind is denied bail”

  1. Carole Theriault

    Is he a suspected mastermind? Or a suspected Mariposa leader? Just wonderin…

    1. He’s the suspected mastermind of the Mariposa botnet. Stop causing trouble Theriault.

What do you think? Leave a comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.