• Home
  • Latest
  • Fortune 500
  • Finance
  • Tech
  • Leadership
  • Lifestyle
  • Rankings
  • Multimedia
TechCisco Systems

Attack on Cisco routers just got a lot bigger

By
Jonathan Vanian
Jonathan Vanian
Down Arrow Button Icon
By
Jonathan Vanian
Jonathan Vanian
Down Arrow Button Icon
September 21, 2015, 5:55 PM ET
A 10801
A 10801Courtesy of Cisco

A major cyber attack on routers from Cisco Systems is worse than previously believed, according to a report Monday by security research group Shadowserver Foundation.

Hackers have installed a nasty type of malware called SYNfull Knock on nearly 200 Cisco routers used by businesses worldwide, the report said. The malware is dangerous because it lets attackers hijack the devices used to direct Internet traffic and steal company data.

Previously, cyber security firm FireEye (FEYE) reported that only 14 Cisco (CSCO) routers of companies in India, Philippines, Mexico, and the Ukraine were infected with the malware. Monday’s report by the Shadowserver Foundation, however, shows that compromised routers can now be found in 31 countries, with 65 of the devices located in the United States.

Based on the report, it seems that the U.S. is a significant target of whoever is responsible for the hacks. India comes in second after the U.S. with 12 tampered routers followed by Russia, which has 11.

The report does not list which companies have been affected. There have been no reports of company information being stolen as a result of the vulnerability.

Shadowserver partnered with Cisco to address the malware attack, according to a blog post written by Omar Santos, a principal engineer of Cisco’s product security incident response team. Both Cisco and Shadowserver are scanning the Internet to determine the severity of the router infections, Santos explained.

“We believe this activity supports Cisco efforts that are already underway to identify and alert customers to potential exposures,” Santos wrote.

The SYNfull Knock malware is said to affect older Cisco router models that are no longer being sold. Cisco recently posted a information online to help users whose equipment is infected with the bug. Last week, a Cisco spokesperson told Reuters that Cisco has reached out to customers and is telling them how to “harden their network, and prevent, detect and remediate this type of attack.”

At that time FireEye CEO Dave DeWalt told Reuters that the malware attack was so sophisticated only “a handful of nation-state actors” could pull it off.

DeWalt did not say which countries are suspected to be responsible for carrying out the attack.

Subscribe to Data Sheet, Fortune’s daily newsletter on the business of technology.

For more on cyber security, check out the following Fortune video:

About the Author
By Jonathan Vanian
LinkedIn iconTwitter icon

Jonathan Vanian is a former Fortune reporter. He covered business technology, cybersecurity, artificial intelligence, data privacy, and other topics.

See full bioRight Arrow Button Icon

Latest in Tech

CryptoYouTube
Exclusive: YouTube launches option for U.S. creators to receive stablecoin payouts through PayPal
By Ben WeissDecember 11, 2025
5 hours ago
Five panelists seated; two women and five men.
AIBrainstorm AI
The race to deploy an AI workforce faces one important trust gap: What happens when an agent goes rogue?
By Amanda GerutDecember 11, 2025
8 hours ago
Stephanie Zhan, Partner Sequoia Capital speaking on stage at Fortune Brainstorm AI San Francisco 2025.
AIEye on AI
Highlights from Fortune Brainstorm AI San Francisco
By Jeremy KahnDecember 11, 2025
8 hours ago
Sam Altman
Arts & EntertainmentMedia
‘We’re not just going to want to be fed AI slop for 16 hours a day’: Analyst sees Disney/OpenAI deal as a dividing line in entertainment history
By Nick LichtenbergDecember 11, 2025
8 hours ago
InnovationBrainstorm AI
Backflips are easy, stairs are hard: Robots still struggle with simple human movements, experts say
By Nicholas GordonDecember 11, 2025
9 hours ago
Iger
AIDisney
‘Creativity is the new productivity’: Bob Iger on why Disney chose to be ‘aggressive,’ adding OpenAI as a $1 billion partner
By Nick LichtenbergDecember 11, 2025
11 hours ago

Most Popular

placeholder alt text
Success
At 18, doctors gave him three hours to live. He played video games from his hospital bed—and now, he’s built a $10 million-a-year video game studio
By Preston ForeDecember 10, 2025
2 days ago
placeholder alt text
Investing
Baby boomers have now 'gobbled up' nearly one-third of America's wealth share, and they're leaving Gen Z and millennials behind
By Sasha RogelbergDecember 8, 2025
3 days ago
placeholder alt text
Success
Palantir cofounder calls elite college undergrads a ‘loser generation’ as data reveals rise in students seeking support for disabilities, like ADHD
By Preston ForeDecember 11, 2025
15 hours ago
placeholder alt text
Economy
‘We have not seen this rosy picture’: ADP’s chief economist warns the real economy is pretty different from Wall Street’s bullish outlook
By Eleanor PringleDecember 11, 2025
20 hours ago
placeholder alt text
Economy
‘Be careful what you wish for’: Top economist warns any additional interest rate cuts after today would signal the economy is slipping into danger
By Eva RoytburgDecember 10, 2025
2 days ago
placeholder alt text
Politics
Exclusive: U.S. businesses are getting throttled by the drop in tourism from Canada: ‘I can count the number of Canadian visitors on one hand’
By Dave SmithDecember 10, 2025
2 days ago
Rankings
  • 100 Best Companies
  • Fortune 500
  • Global 500
  • Fortune 500 Europe
  • Most Powerful Women
  • Future 50
  • World’s Most Admired Companies
  • See All Rankings
Sections
  • Finance
  • Leadership
  • Success
  • Tech
  • Asia
  • Europe
  • Environment
  • Fortune Crypto
  • Health
  • Retail
  • Lifestyle
  • Politics
  • Newsletters
  • Magazine
  • Features
  • Commentary
  • Mpw
  • CEO Initiative
  • Conferences
  • Personal Finance
  • Education
Customer Support
  • Frequently Asked Questions
  • Customer Service Portal
  • Privacy Policy
  • Terms Of Use
  • Single Issues For Purchase
  • International Print
Commercial Services
  • Advertising
  • Fortune Brand Studio
  • Fortune Analytics
  • Fortune Conferences
  • Business Development
About Us
  • About Us
  • Editorial Calendar
  • Press Center
  • Work At Fortune
  • Diversity And Inclusion
  • Terms And Conditions
  • Site Map

© 2025 Fortune Media IP Limited. All Rights Reserved. Use of this site constitutes acceptance of our Terms of Use and Privacy Policy | CA Notice at Collection and Privacy Notice | Do Not Sell/Share My Personal Information
FORTUNE is a trademark of Fortune Media IP Limited, registered in the U.S. and other countries. FORTUNE may receive compensation for some links to products and services on this website. Offers may be subject to change without notice.