Researchers Discover 17,000 Macs in a Botnet

Image result for apple logoPeople who use Apple computers operate under the assumption that they are invulnerable to malware attacks.  This information is reinforced by the Geniuses at the Apple Store, or so I have been told by more than one of my Mac-based clients.  But we have been warning for several years now that this is no longer true.  This must be the case, since Apple introduced a new feature to OSX Snow Leopard in 2009 called XProtect, and has added it to every subsequent distribution.

In any event, at the beginning of October, cybersecurity researchers discovered a 17,000 Mac botnet that was at large on the Internet.  What made this botnet especially interesting was its use of encryption technologies to mask some of its processes, and a link to popular site Reddit, and some several Minecraft servers.

The good news is that Apple released an update around October 6th to its XProtect system that patched the hole that this exploit was using, but this may not “fix” your problem if you are already infected.  The Lifars blog reports that there are risks to Mac users:

What dangers does Mac.BackDoor.iWorm pose to infected Macs?

To name a few, it can:

  • Download further malware
  • Execute remote commands
  • Steal sensitive information
  • Use the hijacked Macs for a DDoS attack
  • Launch spam campaigns

A Mac user in one of my security classes recently asked if there were Internet Security products for the Mac, and I honestly did not know, so I did some checking and found free anti-virus and anti-malware security products for the Mac at both AVG and Sophos.  I suspect that there are plenty of others as well.

Our recommendation for our Apple clients?  Install some of these products to supplement was Apple has already built into their products.  And don’t forget to protect your iPad and iPhone as well.

Wikipedia article on XProtect
AVG Antivirus for the Mac
Lifars:  A New Threat to Mac OS X Users: A Complex Botnet of Over 17,000 Macs Discovered
SC Magazine: Researchers discover Mac botnet
ZD Net:  Apple anti-malware update blocks new ‘iWorm’ Mac botnet


About the Author:

I am a cybersecurity and IT instructor, cybersecurity analyst, pen-tester, trainer, and speaker. I am an owner of the WyzCo Group Inc. In addition to consulting on security products and services, I also conduct security audits, compliance audits, vulnerability assessments and penetration tests. I also teach Cybersecurity Awareness Training classes. I work as an information technology and cybersecurity instructor for several training and certification organizations. I have worked in corporate, military, government, and workforce development training environments I am a frequent speaker at professional conferences such as the Minnesota Bloggers Conference, Secure360 Security Conference in 2016, 2017, 2018, 2019, the (ISC)2 World Congress 2016, and the ISSA International Conference 2017, and many local community organizations, including Chambers of Commerce, SCORE, and several school districts. I have been blogging on cybersecurity since 2006 at

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