Key metrics from the 2H 2021 Netscout Threat Intelligence Report
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United States

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

25

Attack Vectors Used

1. bittorrent amplification
2. chargen amplification
3. cldap amplification
4. dns
5. dns amplification
6. icmp
7. isakmp
8. l2tp amplification
9. mdns amplification
10. memcached amplification
11. ms sql rs amplification
12. netbios amplification
13. ntp amplification
14. openvpn amplification
15. ripv1 amplification
16. rpcbind amplification
17. snmp amplification
18. ssdp amplification
19. stun amplification
20. tcp ack
21. tcp null
22. tcp rst
23. tcp syn
24. tcp syn/ack amplification
25. udp flood

Top 5 Attack Vectors

Ts

TCP SYN

Number of Attacks

228,673

Ta

TCP ACK

Number of Attacks

202,286

Dn

DNS Amplification

Number of Attacks

185,712

Tr

TCP RST

Number of Attacks

155,539

Np

NTP Amplification

Number of Attacks

107,154

Top Ten 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
1
Wired Telecommunications Resellers icon Wired Telecommunications Carriers
147,268 432.93 Gbps 103.68 Mpps 31.2 Minutes
2
cloud icon with up arrow Data Processing, Hosting + Related Services
89,254 278.77 Gbps 76.73 Mpps 72 Minutes
3
radio icon Internet Publishing, Broadcasting + Web Search Portals
54,359 309.06 Gbps 54.16 Mpps 101.8 Minutes
4
cell phone icon Wireless Telecommunications Carriers (except Satellite)
30,710 130.39 Gbps 80.66 Mpps 30.6 Minutes
5
shopping cart icon Electronic Shopping + Mail-Order Houses
30,289 196.48 Gbps 34.81 Mpps 94.3 Minutes
6
laptop icon Electronic Computer Manufacturing
24,940 221.35 Gbps 35.18 Mpps 70.7 Minutes
7
Telecomm Tower icon All Other Telecommunications
6,993 84.85 Gbps 20.68 Mpps 60.5 Minutes
8
Document with PDF icon Software Publishers
6,692 114.09 Gbps 29.01 Mpps 85.4 Minutes
9
stereo speakers icon Audio and Video Equipment Manufacturing
3,773 82.35 Gbps 15.45 Mpps 77.2 Minutes
10
Computer screen with document icon All Other Support Services
3,668 26.95 Gbps 12.09 Mpps 100.5 Minutes