Palo Alto Networks Advanced URL Filtering subscription collects data regarding two types of URLs; landing URLs and host URLs. We define a malicious landing URL as one that allows a user to click a malicious link. A malicious host URL is a page containing a malicious code snippet that could abuse someone’s computing power, steal sensitive information or perform other types of attacks.
Our researchers regularly track web threats to better understand trends that develop over time. This blog will cover trends we’ve identified between April 2022 and June 2022 using our web threat detection module.
Our detection module found around 751,000 incidents of malicious landing URLs containing different kinds of web threats, 253,000 (around one third) of which are unique URLs. In addition, the detection module also detected around 1,740,000 malicious host URLs, 256,000 (almost 15%) of which are unique.
In this blog, we present our analysis and findings of these web threat trends, including the following information:
Palo Alto Networks customers receive protections from the web threats discussed here, as well as many others, via the Advanced URL Filtering, DNS Security and Threat Prevention cloud-delivered security services.
Web Threats Landing URLs: Detection Analysis
Web Threats Malicious Host URLs: Detection Analysis
Indicators of Compromise
Between April and June 2022, we collected data from our customers with our Advanced URL Filtering subscription, within the web threat detection module which uses special YARA signatures. We detected 751,331 incidents of landing URLs, containing all kinds of web threats, such as web skimmers and web scams. 253,644 of these landing URLS were unique. Compared with the results from last quarter (Q1 2022), which had a total of 577,275 detected landing URLs and 116,643 unique URLs, we can see the totals rose in Q2.
Figure 1 shows the total number of web threat hits in Q2 of 2022, how many of those hits were unique, and how many of those hits were also observed last quarter. As we can see, the repeated unique number from Q1 is low, which suggests that attackers are always trying to target new entry points.
According to our analysis, the previously mentioned 253,644 unique URLs are from 34,833 unique domains. After identifying the geographical locations for these domain names, we found the majority of them seem to originate from the United States, followed by Germany and Russia, as was also the case last quarter. However, we recognize attackers are leveraging 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. Figure 3 shows the top eight countries where the owners of these domain names appear to be located.
We analyzed the landing URLs initially identified by our detection model as benign, to find the common targets for these cyberattackers and where they may be trying to fool users. These landing URLs lead to people clicking on malicious host URLs. Going forward, all these landing URLs that lead to malicious code snippets will be marked as malicious by our product.
As shown in Figure 4, the top apparently benign targets are personal sites and blogs, followed by business and economy sites, and computer and internet information sites. Compared to last quarter, computer and internet information sites take third place over shopping sites. Because attackers often try to trick users into following malicious links from seemingly benign sites, we strongly recommend users exercise caution when visiting unfamiliar websites.
With Advanced URL Filtering, we detected 1,744,629 incidents of malicious host URLs from April to June 2022, of which 256,844 are unique URLs. The following section will take a closer look at those malicious host URLs. (“Malicious host URLs” specifically refers to pages containing malicious snippets that could abuse users' computing power, steal sensitive information, and so on).
Although the total number of hits is similar to last quarter’s total, the number of unique hits is much greater. This number rose by 42%, suggesting attackers are trying more variants with malicious behavior.
Figure 5 shows the total number of web threat hits, including those categorized as unique hits.
In our geolocation analysis of host URLS, we discovered that the 256,844 unique malicious host URLs belong to 23,663 unique domains. This is fewer unique domains than we observed for landing URLs.
After identifying the apparent geographical locations for these domain names, we found that the majority of them seem to originate from the United States – as we observe for web threats generally. Figure 6 shows a heat map illustrating these findings.
Figure 7 shows the top eight countries where the owners of these domain names appear to be located. Compared to what we observed for web threats overall – the top three countries were the United States, Germany and Russia – the top three host domain countries for malicious host URLs were the same. This matches our findings from last quarter.
As we did in our yearly analysis, The Year in Web Threats: Web Skimmers Take Advantage of Cloud Hosting and More, we identified pieces of malware as part of a family by checking for certain characteristics: similar code patterns or behaviors, or having originated from the same attacker.
Figure 9 shows the number of snippets observed for the top 10 malware families we identified. As we’ve seen previously, there were fewer families of JS redirectors, web scams and JS downloaders, while web skimmers show more diversity in code and behavior.
We found many websites infected with variants from the same family, which is evolving to evade detection. When we first found this malware family, it was not obfuscated at all. But from a sample we found in the second quarter of 2022, we see it is lightly obfuscated to hide the redirection URL.
As we can see, the snippet is lightly obfuscated with CharCode. After we deobfuscate the sample, we get the code shown in Figure 11.
As we highlighted in this blog, the most prevalent web threats are still JS downloaders, cryptominers, web skimmers, web scams and JS redirectors. Of the landing URLs we analyzed, the top three verticals targeted by attackers were personal sites and blogs, business and economy sites, and computer and internet information sites.
While cybercriminals continue to seek opportunities for malicious cyber activities, Palo Alto Networks customers receive protection from the web threat attacks discussed here as well as many others, via the Advanced URL Filtering, DNS Security and Threat Prevention cloud-delivered security services.
We also recommend the following actions:
If you think you may have been compromised or have an urgent matter, get in touch with the Unit 42 Incident Response team or call:
Malicious Web Skimmer SHA256:
We would like to thank Mike Harbison, Billy Melicher, Alex Starov, Jun Javier Wang and Laura Novak for their help with the blog.
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