Key metrics from the 2H 2021 Netscout Threat Intelligence Report
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Saudi Arabia

The second half of 2021 ushered in a new focus by adversaries, who launched direct-path (non-spoofed) DDoS attacks using botnets and TCP-based floods. This coincided with a drop in DNS and CLDAP amplification, resulting in a decrease in attacks across most countries and regions. The turning point for this decline occurred just before Omicron was discovered, as COVID-19 restrictions were easing and people began returning to physical offices and classrooms. With less time to engage in malicious activity resulting in fewer DDoS attacks, threat actors certainly lend credence to the proverb that idle hands are the devil’s workshop.

Adversaries launched more than 9.7 million DDoS attacks in 2021, just 3% shy of the record-breaking 10 million seen in 2020 and a whopping 14% more than seen pre-pandemic in 2019. So although it’s tempting to simply look at the decrease in overall attacks as threat actors resting on their laurels, the reality is that attackers are innovating and adapting new techniques and methodologies to strengthen and monetize their nefarious behavior.

Max Multivector Attack

Max number of vectors seen in a single attack


Attack Vectors Used

1. bittorrent amplification
2. cldap amplification
3. dns
4. dns amplification
5. icmp
6. mdns amplification
7. memcached amplification
8. ms sql rs amplification
9. netbios amplification
10. ntp amplification
11. openvpn amplification
12. rpcbind amplification
13. sip amplification
14. snmp amplification
15. ssdp amplification
16. tcp ack
17. tcp rst
18. tcp syn
19. tcp syn/ack amplification
20. udp flood

Top 5 Attack Vectors



Number of Attacks



NTP Amplification

Number of Attacks



DNS Amplification

Number of Attacks



TCP SYN/ACK Amplification

Number of Attacks




Number of Attacks


Top Seven Vertical Industries Under Attack

The following industry chart shows the most targeted sectors in 2H 2021 by number of attacks.

Rank Vertical Frequency Max Attack Max Impact Average Duration
Wired Telecommunications Resellers icon Wired Telecommunications Carriers
2,262 82.44 Gbps 15.77 Mpps 35.9 Minutes
Telecomm Tower icon Other Telecommunications
680 0.1 Gbps 0.03 Mpps 22.6 Minutes
cloud icon with up arrow Data Processing, Hosting + Related Services
264 22.37 Gbps 3.74 Mpps 31.1 Minutes
computer storage icon Computer Storage Device Manufacturing
5 1.89 Gbps 0.17 Mpps 5.2 Minutes
Document with PDF icon Software Publishers
2 0.05 Gbps 0.01 Mpps 5 Minutes
monitor and screwdriver icon Computer and Office machine Repair and Maintenance
1 0.56 Gbps 0.05 Mpps 25 Minutes
cell phone icon Wireless Telecommunications Carriers (except Satellite)
1 0.77 Gbps 0.21 Mpps 8 Minutes