One year of war in Ukraine: Internet trends, attacks, and resilience

One year of war in Ukraine: Internet trends, attacks, and resilience

One year of war in Ukraine: Internet trends, attacks, and resilience

The Internet has become a significant factor in geopolitical conflicts, such as the ongoing war in Ukraine. Tomorrow marks one year since the Russian invasion of that country. This post reports on Internet insights and discusses how Ukraine’s Internet remained resilient in spite of dozens of disruptions in three different stages of the conflict.

Key takeaways:

  • Internet traffic shifts in Ukraine are clearly visible from east to west as Ukrainians fled the war, with country-wide traffic dropping as much as 33% after February 24, 2022.
  • Air strikes on energy infrastructure starting in October led to widespread Internet disruptions that continue in 2023.
  • Application-layer cyber attacks in Ukraine rose 1,300% in early March 2022 compared to pre-war levels.
  • Government administration, financial services, and the media saw the most attacks targeting Ukraine.
  • Traffic from a number of networks in Kherson was re-routed through Russia between June and October, subjecting traffic to Russia’s restrictions and limitations, including content filtering. Even after traffic ceased to reroute through Russia, those Ukrainian networks saw major outages through at least the end of the year, while two networks remain offline.
  • Through efforts on the ground to repair damaged fiber optics and restore electrical power, Ukraine’s networks have remained resilient from both an infrastructure and routing perspective. This is partly due to Ukraine’s widespread connectivity to networks outside the country and large number of IXPs.
  • Starlink traffic in Ukraine grew over 500% between mid-March and mid-May, and continued to grow from mid-May through mid-November, increasing nearly 300% over that six-month period. For the full period from mid-March (two weeks after it was made available) to mid-December, it was over a 1,600% increase, dropping a bit after that.

Internet changes and disruptions

An Internet shock after February 24, 2022

In Ukraine, human Internet traffic dropped as much as 33% in the weeks following February 24. The following chart shows Cloudflare’s perspective on daily traffic (by number of requests).

One year of war in Ukraine: Internet trends, attacks, and resilience

Internet traffic levels recovered over the next few months, including strong growth seen in September and October, when many Ukrainian refugees . Those outages lasted until September 10, as shown in the charts below.

One year of war in Ukraine: Internet trends, attacks, and resilience

One year of war in Ukraine: Internet trends, attacks, and resilience

More broadly, the city of Enerhodar, where the nuclear power plant is located, experienced a four-day outage after September 6.

Mid-September traffic drop in Crimea

In mid-September, following Ukraine’s counteroffensive, there were questions as to when Crimea might be targeted by Ukrainian forces, with news reports indicating that there was an evacuation of the Russian population from Crimea around September 13. We saw a clear drop in traffic on that Tuesday, compared with the previous day, as seen in the map of Crimea below (red is decrease in traffic, green is increase).

One year of war in Ukraine: Internet trends, attacks, and resilience

October brings energy infrastructure attacks and country-wide disruptions

As we have seen, the Russian air strikes targeting critical energy infrastructure began in September as a retaliation to Ukraine’s counteroffensive. The following month, the Crimean Bridge explosion on Saturday, October 8 (when a truck-borne bomb destroyed part of the bridge) led to more air strikes that affected networks and Internet traffic across Ukraine.

On Monday, October 10, Ukraine woke up to air strikes on energy infrastructure and experienced severe electricity and Internet outages. At 07:35 UTC, traffic in the country was 35% below its usual level compared with the previous week and only fully recovered more than 24 hours later. The impact was particularly significant in regions like Kharkiv, where traffic was down by around 80%, and Lviv, where it dropped by about 60%. The graph below shows how new air strikes in Lviv Oblast the following day affected Internet traffic.

One year of war in Ukraine: Internet trends, attacks, and resilience

There were clear disruptions in Internet connectivity in several regions on October 17, but also on October 20, when the destruction of several power stations in Kyiv resulted in a 25% drop in Internet traffic from Kyiv City as compared to the two previous weeks. It lasted 12 hours, and was followed the next day by a shorter partial outage as seen in the graph below.

One year of war in Ukraine: Internet trends, attacks, and resilience

In late October, according to Ukrainian officials, 30% of Ukraine’s power stations were destroyed. Self-imposed power limitations because of this destruction resulted in drops in Internet traffic observed in places like Kyiv and the surrounding region.

The start of a multi-week Internet disruption in Kherson Oblast can be seen in the graph below, showing ~70% lower traffic than in previous weeks. The disruption began on Saturday, October 22, when Ukrainians were gaining ground in the Kherson region.

One year of war in Ukraine: Internet trends, attacks, and resilience

Traffic began to return after Ukrainian forces took Kherson city on November 11, 2022. The graph below shows a week-over-week comparison for Kherson Oblast for the weeks of November 7, November 28, and December 19 for better visualization in the chart while showing the evolution through a seven-week period.

One year of war in Ukraine: Internet trends, attacks, and resilience

Ongoing strikes and Internet disruptions

Throughout the rest of the year and into 2023, Ukraine has continued to face intermittent Internet disruptions. On November 23, 2022, the country experienced widespread power outages after Russian strikes, causing a nearly 50% decrease in Internet traffic in Ukraine. This disruption lasted for almost a day and a half, further emphasizing the ongoing impact of the conflict on Ukraine’s infrastructure.

One year of war in Ukraine: Internet trends, attacks, and resilience

Although there was a recovery after that late November outage, only a few days later traffic seemed closer to normal levels. Below is a chart of the week-over-week evolution of Internet traffic in Ukraine at both a national and local level during that time:

One year of war in Ukraine: Internet trends, attacks, and resilience

In Kyiv Oblast:

One year of war in Ukraine: Internet trends, attacks, and resilience

In the Odessa region:

One year of war in Ukraine: Internet trends, attacks, and resilience

And Kharkiv (where a December 16 outage is also clear — in the green line):

One year of war in Ukraine: Internet trends, attacks, and resilience

On December 16, there was another country-level Internet disruption caused by air strikes targeting energy infrastructure. Traffic at a national level dropped as much as 13% compared with the previous week, but Ukrainian networks were even more affected. AS13188 (Triolan) had a 70% drop in traffic, and AS15895 (Kyivstar) a 40% drop, both shown in the figures below.

One year of war in Ukraine: Internet trends, attacks, and resilience

One year of war in Ukraine: Internet trends, attacks, and resilience

In January 2023, air strikes caused additional Internet disruptions. One such recent event was in Odessa, where traffic dropped as low as 54% compared with the previous week during an 18-hour disruption.

A cyber war with global impact

“Shields Up” on cyber attacks

The US government and the FBI issued warnings in March to all citizens, businesses, and organizations in the country, as well as allies and partners, to be aware of the need to “enhance cybersecurity.” The US Cybersecurity and Infrastructure Security Agency (CISA) launched the Shields Up initiative, noting that “Russia’s invasion of Ukraine could impact organizations both within and beyond the region.” The UK and Japan, among others, also issued warnings.

Below, we discuss Web Application Firewall (WAF) mitigations and DDoS attacks. A WAF helps protect web applications by filtering and monitoring HTTP traffic between a web application and the Internet. A WAF is a protocol layer 7 defense (in the OSI model), and is not designed to defend against all types of attacks. Distributed Denial of Service (DDoS) attacks are cyber attacks that aim to take down Internet properties and make them unavailable for users.

Cyber attacks rose 1,300% in Ukraine by early March

The charts below are based on normalized data, and show threats mitigated by our WAF.

Mitigated application-layer threats blocked by our WAF skyrocketed after the war started on February 24. Mitigated requests were 105% higher on Monday, February 28 than in the previous (pre-war) Monday, and peaked on March 8, reaching 1,300% higher than pre-war levels.

Between February 2022 and February 2023, an average of 10% of all traffic to Ukraine was mitigations of potential attacks.

The graph below shows the daily percentage of application layer traffic to Ukraine that Cloudflare mitigated as potential attacks. In early March, 30% of all traffic was mitigated. This fell in April, and remained low for several months, but it picked up in early September around the time of the Ukrainian counteroffensive in east and south Ukraine. The peak was reached on October 29 when DDoS attack traffic constituted 39% of total traffic to Cloudflare’s Ukrainian customer websites.

One year of war in Ukraine: Internet trends, attacks, and resilience

This trend is more evident when looking at all traffic to sites on the “.ua” top-level domain (from Cloudflare’s perspective). The chart below shows that DDoS attack traffic accounted for over 80% of all traffic by early March 2022. The first clear spikes occurred on February 16 and 19, with around 25% of traffic mitigated. There was no moment of rest after the war started, except towards the end of November and December, but the attacks resumed just before Christmas. An average of 13% of all traffic to “.ua”, between February 2022 and February 2023 was mitigations of potential attacks. The following graph provides a comprehensive view of DDoS application layer attacks on “.ua” sites:

One year of war in Ukraine: Internet trends, attacks, and resilience

Moving on to types of mitigations of product groups that were used (related to “.ua” sites), as seen in the next chart, around 57% were done by the ruleset which automatically detects and mitigates HTTP DDoS attacks (DDoS Mitigation), 31% were being mitigated by firewall rules put in place (WAF), and 10% were blocking requests based on our IP threat reputation database (IP Reputation).

One year of war in Ukraine: Internet trends, attacks, and resilience

It’s important to note that WAF rules in the graph above are also associated with custom firewall rules created by customers to provide a more tailored protection. “DDoS Mitigation” (application layer DDoS protection) and “Access Rules” (rate limiting) are specifically used for DDoS protection.

In contrast to the first graph shown in this section, which looked at mitigated attack traffic targeting Ukraine, we can also look at mitigated attack traffic originating in Ukraine. The graph below also shows that the share of mitigated traffic from Ukraine also increased considerably after the invasion started.

One year of war in Ukraine: Internet trends, attacks, and resilience

Top attacked industries: from government to news media

The industries sectors that had a higher share of WAF mitigations were government administration, financial services, and the media, representing almost half of all WAF mitigations targeting Ukraine during 2022.

Looking at DDoS attacks, there was a surge in attacks on media and publishing companies during 2022 in Ukraine. Entities targeting Ukrainian companies appeared to be focused on information-related websites. The top five most attacked industries in the Ukraine in the first two quarters of 2022 were all in broadcasting, Internet, online media, and publishing, accounting for almost 80% of all DDoS attacks targeting Ukraine.

In a more focused look at the type of websites Cloudflare has protected throughout the war, the next two graphs provide a view of mitigated application layer attacks by the type of “.ua” sites we helped to protect. In the first days of the war, mitigation spikes were observed at a news service, a TV channel, a government website, and a bank.

One year of war in Ukraine: Internet trends, attacks, and resilience

In July, spikes in mitigations we observed across other types of “.ua” websites, including food delivery, e-commerce, auto parts, news, and government.

One year of war in Ukraine: Internet trends, attacks, and resilience

More recently, in February 2023, the spikes in mitigations were somewhat similar to what we saw one year ago, including electronics, e-commerce, IT, and education websites.

One year of war in Ukraine: Internet trends, attacks, and resilience

12.6% of network-layer traffic was DDoS activity in Q1 2022

Network-layer (layer 3 and 4) traffic is harder to attribute to a specific domain or target because IP addresses are shared across different customers. Looking at network-level DDoS traffic hitting our Kyiv data center, we saw peaks of DDoS traffic higher than before the war in early March, but they were much higher in June and August.

One year of war in Ukraine: Internet trends, attacks, and resilience

In our Q1 2022 DDoS report, we also noted that 12.6% of Ukraine’s traffic was DDoS activity, compared with 1% in the previous quarter, a 1,160% quarter-over-quarter increase.

Several of our quarterly DDoS reports from 2022 include attack trends related to the war in Ukraine, with quarter over quarter interactive comparisons.

Network re-routing in Kherson

On February 24, 2022, Russian forces invaded Ukraine’s Kherson Oblast region. The city of Kherson was captured on March 2, as the first major city and only regional capital to be captured by Russian forces during the initial invasion. The Russian occupation of Kherson Oblast continued until Ukrainian forces resumed control on November 11, after launching a counteroffensive at the end of August.

On May 4, 2022, we published Tracking shifts in Internet connectivity in Kherson, Ukraine, a blog post that explored a re-routing event that impacted AS47598 (Khersontelecom), a telecommunications provider in Kherson Oblast. Below, we summarize this event, and explore similar activity across other providers in Kherson that has taken place since then.

On May 1, 2022, we observed a shift in routing for the IPv4 prefix announced by Ukrainian network AS47598 (Khersontelecom). During April, it reached the Internet through several other Ukrainian network providers, including AS12883 (Vega Telecom) and AS3326 (Datagroup). However, after the shift, its routing path now showed a Russian network, AS201776 (Miranda-Media), as the sole upstream provider. With traffic from KhersonTelecom passing through a Russian network, it was subject to the restrictions and limitations imposed on any traffic transiting Russian networks, including content filtering.

The flow of traffic from Khersontelecom before and after May 1, with rerouting through Russian network provider Miranda-Media, is illustrated in the chart below. This particular re-routing event was short-lived, as a routing update for AS47598 on May 4 saw it return to reaching the Internet through other Ukrainian providers.

One year of war in Ukraine: Internet trends, attacks, and resilience

As a basis for our analysis, we started with a list of 15 Autonomous System Numbers (ASNs) belonging to networks in Kherson Oblast. Using that list, we analyzed routing information collected by route-views2 over the past year, from February 1, 2022, to February 15, 2023. route-views2 is a BGP route collector run by the University of Oregon Route Views Project. Note that with respect to the discussions of ASNs in this and the following section, we are treating them equally, and have not specifically factored estimated user population into these analyses.

The figure below illustrates the result of this analysis, showing that re-routing of Kherson network providers (listed along the y-axis) through Russian upstream networks was fairly widespread, and for some networks, has continued into 2023. During the analysis time frame, there were three primary Russian networks that appeared as upstream providers: AS201776 (Miranda-Media), AS52091 (Level-MSK Ltd.), and AS8492 (OBIT Ltd.).

Within the graph, black bars indicate periods when the ASN effectively disappeared from the Internet; white segments indicate the ASN was dependent on other Ukraine networks as immediate upstreams; and red indicates the presence of Russian networks in the set of upstream providers. The intensity of the red shading corresponds to the percentage of announced prefixes for which a Russian network provider is present in the routing path as observed from networks outside Ukraine. Bright red shading, equivalent to “1” in the legend, indicates the presence of a Russian provider in all routing paths for announced prefixes.

One year of war in Ukraine: Internet trends, attacks, and resilience

In the blog post linked above, we referenced an outage that began on April 30. This is clearly visible in the figure as a black bar that runs for several days across all the listed ASNs. In this instance, AS47598 (KhersonTelecom) recovered a day later, but was sending traffic through AS201776 (Miranda-Media), a Russian provider, as discussed above.

Another Ukrainian network, AS49168 (Brok-X), recovered from the outage on May 2, and was also sending traffic through Miranda-Media. By May 4, most of the other Kherson networks recovered from the outage, and both AS47598 and AS49168 returned to using Ukrainian networks as immediate upstream providers. Routing remained “normal” until May 30. Then, a more widespread shift to routing traffic through Russian providers began, although it appears that this shift was preceded by a brief outage for a few networks. For the most part, this re-routing lasted through the summer and into October. Some networks saw a brief outage on October 17, but most stopped routing directly through Russia by October 22.

However, this shift away from Russia was followed by periods of extended outages. KhersonTelecom suffered such an outage, and has remained offline since October, except for the first week of November when all of its traffic routed through Russia. Many other networks rejoined the Internet in early December, relying mostly on other Ukrainian providers for Internet connectivity. However, since early December, AS204485 (PE Berislav Cable Television), AS56359 (CHP Melnikov Roman Sergeevich), and AS49465 (Teleradiocompany RubinTelecom Ltd.) have continued to use Miranda-Media as an upstream provider, in addition to experiencing several brief outages. In addition, over the last several months, AS25082 (Viner Telecom) has used both a Ukrainian network and Miranda-Media as upstream providers.

Internet resilience in Ukraine

In the context of the Internet, “resilience” refers to the ability of a network to operate continuously in a manner that is highly resistant to disruption. This includes the ability of a network to: (1) operate in a degraded mode if damaged, (2) rapidly recover if failure does occur, and (3) scale to meet rapid or unpredictable demands. Throughout the Russia-Ukraine conflict, media coverage (VICE, Bloomberg, Washington Post) has highlighted the work done in Ukraine to repair damaged fiber-optic cables and mobile network infrastructure to keep the country online. This work has been critically important to maintaining the resilience of Ukrainian Internet infrastructure.

According to PeeringDB, as of February 2023, there are 25 Internet Exchange Points (IXPs) in Ukraine and 50 interconnection facilities. (An IXP may span multiple physical facilities.) Within this set of IXPs, Autonomous Systems (ASes) belonging to international providers are currently present in over half of them. The number of facilities, IXPs, and international ASes present in Ukraine points to a resilient interconnection fabric, with multiple locations for both domestic and international providers to exchange traffic.

To better understand these international interconnections, we first analyze the connectivity of ASes in Ukraine, and we classify the links to domestic networks (links where both ASes are registered in Ukraine) and international networks (links between ASes in Ukraine and ASes outside Ukraine). To determine which ASes are domestic in Ukraine, we can use information from the extended delegation reports from the Réseaux IP Européens Network Coordination Centre (RIPE NCC), the Regional Internet Registry that covers Ukraine. We also parsed collected BGP data to extract the AS-level links between Ukrainian ASes and ASes registered in a different country, and we consider these the international connectivity of the domestic ASes.

A March 2022 article in The Economist noted that “For one thing, Ukraine boasts an unusually large number of internet-service providers—by one reckoning the country has the world’s fourth-least-concentrated Internet market. This means the network has few choke points, so is hard to disable.” As of the writing of this blog post, there are 2,190 ASes registered in Ukraine (UA ASes), and 1,574 of those ASes appear in the BGP routing table as active. These counts support the article’s characterization, and below we discuss several additional observations that reinforce Ukraine’s Internet resilience.

One year of war in Ukraine: Internet trends, attacks, and resilience

The figure above is a cumulative distribution function showing the fraction of domestic Ukrainian ASes that have direct connections to international networks. In February 2023, approximately 50% had more than one (100) international link, while approximately 10% had more than 10, and approximately 2% had 100 or more. Although these numbers have dropped slightly over the last year, they underscore the lack of centralized choke points in the Ukrainian Internet.

For the networks with international connectivity, we can also look at the distribution of “next-hop” countries – countries with which those international networks are associated. (Note that some networks may have a global footprint, and for these, the associated country is the one recorded in their autonomous system registration.) Comparing the choropleth maps below illustrates how this set of countries, and their fraction of international paths, have changed between February 2022 and February 2023. The data underlying these maps shows that international connectivity from Ukraine is distributed across 18 countries — unsurprisingly, mostly in Europe.

One year of war in Ukraine: Internet trends, attacks, and resilience

In February 2022, these countries/locations accounted for 77% of Ukraine’s next-hop international paths. The top four all had 7.8% each. However, in February 2023, the top 10 next-hop countries/locations dropped slightly to 76% of international paths. While just a slight change from the previous year, the set of countries/locations and many of their respective fractions saw considerable change.

February 2022
February 2023

1
Germany
7.85%
Russia
11.62%

2
Netherlands
7.85%
Germany
11.43%

3
United Kingdom
7.83%
Hong Kong
8.38%

4
Hong Kong
7.81%
Poland
7.93%

5
Sweden
7.77%
Italy
7.75%

6
Romania
7.72%
Turkey
6.86%

7
Russia
7.67%
Bulgaria
6.20%

8
Italy
7.64%
Netherlands
5.31%

9
Poland
7.60%
United Kingdom
5.30%

10
Hungary
7.54%
Sweden
5.26%

Russia’s share grew by 50% year to 11.6%, giving it the biggest share of next-hop ASes. Germany also grew to account for more than 11% of paths.

One year of war in Ukraine: Internet trends, attacks, and resilience

Satellite Internet connectivity

Cloudflare observed a rapid growth in Starlink’s ASN (AS14593) traffic to Ukraine during 2022 and into 2023. Between mid-March and mid-May, Starlink’s traffic in the country grew over 530%, and continued to grow from mid-May up until mid-November, increasing nearly 300% over that six-month period — from mid-March to mid-December the growth percentage was over 1600%. After that, traffic stabilized and even dropped a bit during January 2023.

One year of war in Ukraine: Internet trends, attacks, and resilience

Our data shows that between November and December 2022, Starlink represented between 0.22% and 0.3% of traffic from Ukraine, but that number is now lower than 0.2%.

One year of war in Ukraine: Internet trends, attacks, and resilience

Conclusion

One year in, the war in Ukraine has taken an unimaginable humanitarian toll. The Internet in Ukraine has also become a battleground, suffering attacks, re-routing, and disruptions. But it has proven to be exceptionally resilient, recovering time and time again from each setback.

We know that the need for a secure and reliable Internet there is more critical than ever. At Cloudflare, we’re committed to continue providing tools that protect Internet services from cyber attack, improve security for those operating in the region, and share information about Internet connectivity and routing inside Ukraine.

Source:: CloudFlare