This post is also available in: 日本語 (Japanese)
It’s no secret that web threats, fueled by sophisticated attackers, continue to increase and do more damage. As part of our regular tracking and observation of trends in web threats, from October 2020 to September 2021, our web threat detection module found around 2,240,000 incidents of malicious landing URLs containing all kinds of web threats, 831,000 of which are unique URLs.
We analyzed these web threats in search of trends in when web threats are more active, which malware families present threats more often, and where in the world web threats appear to be coming from. In many cases, the majority appear to originate from the United States (though we recognize that attackers may use proxy servers to hide their physical locations).
We also take a closer look at the web skimmer. With the popularity of e-commerce websites, web skimmer attacks are being leveraged by more attackers due to the difficulty in detecting them and the ease of deploying them. We will provide insight into how the attack is distributed. We observe that more and more web skimmers are being hosted on the cloud, especially for some web skimmer families.
|Types of Attacks and Vulnerabilities Covered||Skimmer attacks, formjacking, malware, cryptominers|
|Related Unit 42 Topics||Information stealing, A Closer Look at the Web Skimmer|
By collecting data from October 2020-September 2021 with Advanced URL Filtering, we detected 2,241,354 incidents of malicious landing URLs containing all kinds of web threats, 831,550 of which are unique URLs.
As shown in Figure 1, web threats were more active from October 2020-January 2021 than at other times during the year. This suggests that attackers, especially those targeting e-commerce websites, might be more active during the holiday shopping season. After January 2021, the number of web threats leveled off, both in total and in terms of unique URLs.
According to our analysis, the previously mentioned 831,550 unique URLs are from 51,985 unique domains. After identifying the geographical locations for these domain names, we found that the majority number of them seem to originate from the United States, followed by Russia and Germany. However, we recognize that the attackers might leverage proxy servers and VPNs located in those countries to hide their actual physical locations.
The choropleth map shown in Figure 2 indicates the wide distribution of these domain names across almost every continent, including Africa and Australia. Figure 3 shows the top eight countries where the owners of these domain names appear to be located.
The top five web threats we observed are cryptominers, JS downloaders, web skimmers, web scams and JS redirectors. Here are definitions for each:
- Cryptominers or coinminers are cryptocurrency miners that run in web browsers and consume significant CPU resources, making computer use slow.
- Web scams are fraudulent activity over the internet, often using social engineering techniques to propagate malware infection or cause monetary loss for users.
As shown in Figure 4, JS downloader threats are very active. We also see that many coinminers exist all over the web, though, ironically, some are not working because the dependent coinminer libraries they once used are no longer supported. Web skimmers, which we will highlight in the sections that follow, are some of the most pervasive and severe web threats and third most common among the threats we observed.
As we mentioned earlier, web skimmers are easy to deploy and hard to detect. Normally, they will intercept sensitive information such as PII, bank card information and so on. Recently, we noticed that more and more web skimmers were deployed on the cloud to make them seem less suspicious. (When deployed on the cloud, their domain names often contain public cloud indicators tied to legitimate companies, which can increase their apparent legitimacy in the eyes of the user.) In the following sections, we will take a closer look at the web skimmer.
With Advanced URL Filtering, from October 2020-September 2021, we detected 147,907 unique URLs from 611,811 total URLs where web skimmer malware was injected into the pages. These URLs belong to 6,817 unique domains. After identifying the apparent geographical locations for these domain names, we found that the majority of them seem to also originate from the United States – as we observed for web threats generally. Figure 6 shows the heat map.
Figure 7 shows the top eight countries where the owners of these domain names appear to be located. In contrast to what we observed for web threats overall – for which the top three countries were the United States, Russia and Germany – the top three host domain countries for web skimmers were the United States, Germany and the United Kingdom. This seems reasonable since most web skimmers target e-commerce websites and these countries have relatively higher consuming capability.
With e-commerce booming, sophisticated attackers choose to leverage the web skimmer to collect users’ sensitive information. In addition, they increasingly choose to deploy web skimmers in the cloud, especially for some web skimmer families – a practice that can make these pages appear more legitimate to normal users. As Figure 8 shows, we can see the ratio for web skimmers hosted on the cloud is very high for certain families – for example, for web skimmer family 5, almost half of web skimmers are hosted in the cloud. Moreover, the rate for that family grew over 50% from May to September.
The web threats analyzed in this blog indicate that the most prevalent web threats are cryptominers, JS downloaders, web skimmers, web scams and JS redirectors.
The prevalence of web threats emphasizes the need for website administrators to patch all systems, components and web plugins and implement security best practices, which will help to minimize the likelihood of compromised systems.
While cybercriminals continue to seek opportunities for malicious cyber activities, Palo Alto Networks customers are protected from the web threat attacks discussed here and many others via the Advanced URL Filtering and Threat Prevention cloud-delivered security subscriptions.
We also recommend the following actions:
- Continuously update your Next-Generation Firewalls with the latest Palo Alto Networks Threat Prevention content.
- Run a Best Practice Assessment to improve your security posture.
If you think you may be experiencing an active breach, the Unit 42 Incident Response team can help. Please email email@example.com or call (866) 486-4842 – (866) 4-UNIT42 – for U.S. toll free, (31-20) 299-3130 in EMEA or (65) 6983-8730 in JAPAC. The Unit 42 Incident Response team is available 24/7/365.
We would like to thank Billy Melicher, Alex Starov, Jun Javier Wang, Laura Novak and Erica Naone for their help with the blog.