Phishing has pumped up its frequency to being present in 36% of breaches (up from 25% last year).
Network end users are frontline defenders that form a critical component of an organization's information security program. That’s why all cybersecurity training materials include sections on how to spot phishing, which is both rampant and increasingly sophisticated in the methods used to lure victims. When our consultants evaluate risk within an organization and discuss their phishing awareness and training efforts, we typically see advice such as “Don't click on suspicious links” and “Hover the mouse pointer over links in an email to check whether it is legitimate.” But how do you know whether a link and the associated Uniform Resource Locator (URL) lead to a legitimate site?
To evaluate links and URLs, you should understand generic Top-Level Domains (gTLDs), country code TLDs (ccTLDs), and other types of Internet domains. This article covers the basics about reading and interpreting links/URLs.
A web address looks pretty suspicious if you see “www1” or “www2” (or some other number) in the URL. But that's not a definite red flag. Some web sites may be very popular and, therefore, have multiple servers working in a load-balancing configuration to serve content when requested. Some companies choose to number their servers. So, if you see a www1 or www2, you’re just seeing which server # among multiple servers is providing the content. Seeing a www1, www2, etc., is not in itself an indicator of a phishing site.
One way to teach users to look for indicators like these is by developing a customized training program that includes phishing awareness and testing. A training consultant can develop a set of simulated phishing messages that help users learn to spot red flags. When users click the simulated malicious links, the program can point them to additional training.
So what’s the key to reading URLs in links? The basic answer is that interpreting the URL means focusing on the important stuff between the double forward-slash “//” and the first single slash, primarily in the highlighted area shown below.
Note: The framework above is the basic URL breakdown. In place of http:// or https://, you may see ftp:// or news://. These are different types of transfer protocols. In addition, though “www” appears in many URLs, it is not a required component. You may see additional fields prior to the generic top-level domain and secondary domain/server name. (After the first single forward slash, you’ll find less critical things such as directories, subdirectories, filenames and file types.)
With that background information in mind, let’s look at some examples.
This is a well-known site, and the URL doesn’t include any suspicious modifications.
URLs can be formed in almost any fashion, which makes it easy for site owners to build unique site names. It also makes it easy for phishers to build site names that closely approximate legitimate site names.
In this example, a period makes all the difference. If a person clicked on the link above, they wouldn’t go to amazon.com. The link leads to the site zon.com, which could be a site registered by phishers.
In this case, a person would be directed to IP address 22.214.171.124, not amazon.com. If you see a link/URL with an “@” sign, be particularly careful. Phishers routinely use this URL-manipulation tactic.
This URL is somewhat similar in function to #3 above. It leads to the IP address, not amazon.com, which is listed after the first single forward slash.
This URL would refer a person from one site (in this case, google.com) to another site, badsite.com (note the “=http://” nomenclature that allows this). Referrals are not in themselves bad, but a referral could lead to a phishing site. In this case, badsite.com doesn’t look legitimate.
To help users quickly determine the top-level and secondary domains within a URL, some companies and organizations have started to use “domain highlighting.” When a user visits a site, part of the URL will dim after a few seconds, leaving the top-level and secondary domains dark. For example:
It’s always good to look for these signs of a legitimate, secure site:
If a site’s certificate is expired or otherwise invalid, some browsers, such as Internet Explorer and Firefox, or security services, will warn users. Is it safe to proceed through the warning? In this case, use other available indicators (review the URL again) to help determine whether the site is legitimate. If in doubt, do not proceed.
Fifty-four countries have chosen to allow their ccTLDs to be used for commercial purposes. For example, .co, the ccTLD for Colombia, can be used in place of .com. It’s very popular, due to the burgeoning .com domain, and allows businesses to have alternative ways to form website names.
Have you seen the URL http://o.co? That’s Overstock.com providing an alternate way for you to get to the company through your browser.
You may have seen youtu.be. That’s a legitimate URL, registered by Google using Belgium’s ccTLD, .be.
Much of the entertainment industry uses Tavalu’s ccTLD, .TV. It’s a great way for the island nation to make money.
When trying to determine whether a site is legitimate, realize that many ccTLDs are also used for commercial purposes. What looks like a suspicious site could be, in fact, legitimate. However, ccTLDs can also be used to form names for phishing sites, so when in doubt, don’t click!
We are all used to seeing gTLDs. We use them almost every day, including familiar ones such as .com, .gov and .edu. They are a key part of the structure of the Internet. They are also well understood by phishers, who manipulate URLs for fraudulent use. To best assess links within emails, as well as URLs within browsers, it’s good to know how the various domains have evolved and how they work.
In 1984, Request for Comments (RFC) 920 was used to define the original “general purpose domains”: .com, .gov, .mil, .edu, and .org. Another domain, .net, was added in early 1985 and is also considered one of the “original” domains. In 1988, .int (international) was added to meet the North Atlantic Treaty Organization’s request for a domain. Over the years, other domains were added, such as .biz and .info (2001). By early 2011, 22 gTLDs had been established. In June 2011, the Internet Corporation for Assigned Names and Numbers (ICANN) voted to remove many of the restrictions on gTLD applications and implementation, effectively opening the door for almost any gTLD to be used. Under the new rules, there are currently about 1,500 gTLDs, including .auto, .computer, .network, .social, .pizza, .organic, registered and cleared for use on the Internet. According to some security experts, this evolution in gTLDs is considered a gift to phishers because it will allow them to form a multitude of new phishing websites. For a full listing of the expanded gTLDs, see the Internet Assigned Numbers Authority (IANA) Root Zone Database (https://www.iana.org/domains/root/db).
Country code TLDs are also part of many URLs, and, therefore, one can expect to see them in links on occasion. Countries have ccTLDs to help distinguish what country a site is registered in or originates from. For example, the ccTLD for the United States, .us, is often used by state and local governments. Other ccTLD examples are Australia, .au; Japan, .jp; and United Kingdom, .uk. When reading a link or URL, realize that the location of the ccTLD within the URL could shift (at the end of a URL, such as http://www.gov.uk, or earlier in a URL, such as https ://uk.news.yahoo.com).
Phishing continues to be a global problem, exacerbated by users who are unaware of phishing tactics, increasingly sophisticated phishing methods, and now, an increasing set of generic Top-Level Domains. Though links in emails aren’t phishers’ only method, they’re very common. To reduce the risks posed by phishing, you should know how to interpret links and the associated URLs.
At one time, everyone considered intrusion detection (IDS) or prevention (IPS) systems critical to overall information security success. But in recent years, observers keep declaring IDS/IPS dead, only to see it keep hanging on. And while we’re still not ready to bury IDS/IPS today, we DO urge you to consider how you’re deploying these tools within your overall information security strategy. Without proper tuning and deployment, IDS/IPS solutions can't do their jobs properly. And the current landscape of cloud computing and dispersed workforces means protection tied to a firewall misses a lot of activity. Read on to learn how to properly leverage IDS/IPS in a modern environment.
The goal of IDS is to detect cyberattacks by analyzing the signature of data packets as they traverse the network. When the system detects a suspicious packet, it generates an alert. IDS is a passive tool that simply detects and alerts. IPS goes a step farther by adding an active protection method of adapting to the threat and blocking the traffic from reaching the intended victim host. Most IDS/IPS solutions are now available as a bundle with your firewall subscription.
To effectively use IDS/IPS systems, you should be aware of a couple of inherent limitations:
Follow these steps to ensure that these tools provide the protection you’re expecting:
For help reviewing your security system’s architecture, contact us today.
Here’s the hard truth about monitoring solutions: Most companies haven’t properly configured their SIEM/XDR system. Logging millions of events per day may seem productive. But what good does it do if an IT team is overwhelmed with alert fatigue and learns to ignore most of notifications they get?
“The basic rules in your SIEM may be functioning, but they often aren’t functioning well,” says Pratum Chief Technology Officer Steve Healey. Read on to learn how trained SOC analysts leverage SIEM/XDR tuning to turn out-of-the-box rules into meaningful tools for reducing noise and alert fatigue while stopping attacks before they gain a foothold.
All SIEM solutions come pre-loaded with a large number of rules. Alert fatigue happens because standard rules can’t possibly work equally well in every environment. “The idea behind those rules is solid, but they’re generic,” Steve says. “The execution will lead to an enormous number of false positives and alert fatigue. You’ll have to tune the rules with additional logic specific to your business to create exceptions without impeding the rule’s original intent.”
Beyond SIEM vendors, many other tech vendors regularly issue new detection rules to close gaps discovered in their own products. Many of those rules also generate a flood of false positives. Pratum’s SOC analysts (who have managed multi-tenant SIEM/XDR solutions for more than a decade) review each new rule’s goal and customize it for every customer’s environment. “We don’t just disable ineffective rules,” Steve says. “We take the core intent of the rule and build it out to get high-fidelity results.” With this kind of tuning, Pratum recently turned 266 million monthly security events in one client’s environment into just 41 alerts sent to the client’s IT team.
The real art of creating SIEM/XDR rules lies in finding the sweet spot of writing rules sensitive enough to detect real threats but not so sensitive that they cause constant false positives. Nobody wants to get an alert every time someone logs in from a coffee shop using a different IP address. But if a legitimate user who normally uses an iPhone suddenly logs in through an Android device in a new geographic location, that’s worth an alert.
The solution is a team of SOC analysts trained to create models of normal activity. By identifying patterns of typical activity, analysts help the system recognize a scenario that checks all the boxes to be suspicious—but actually isn’t. “We can create threat models based on baseline behavior so we know what’s normal and only send an alert when the pattern changes,” Steve says. “Machine learning can figure that out over time.”
The following real-world scenarios illustrate how SIEM tuning modified standard rules into more accurate reporting tools that stop the alert fatigue.
Pratum recently revised one rule intended to deal with the growing threat of business email compromise (BEC) attacks. In these situations, hackers take over a legitimate user account. Then they often create email forwarding rules that let them intercept a user’s messages and conceal the fact that the account has been compromised. Many SIEM solutions now include a stock alert designed to watch for the creation of suspicious forwarding rules. But Pratum’s analysts recognized that the stock rule wasn’t catching the forwarding rule hackers are using most right now. So Pratum’s SOC team wrote a new rule, had the Pratum penetration testing team attempt an exploit to validate the rule, then rolled the rule out to Pratum’s entire client base. The new rule not only identifies the activity, but can also automatically orchestrate a response to contain the threat.
“The intent of most rules is terrific. A lot of rules would be amazing if they were accurate 100% of the time. But they aren’t,” Steve says. Pratum’s SOC team noticed that one stock rule started generating 50 tickets a day for every organization Pratum manages. Less than 5% of the alerts were legitimate threats because the rule kept triggering when normal software operations took place.
The analysts disabled the rule to stop the flood of unactionable data, then rewrote it with complex logic that cut the false positives to almost zero. “Within 72 hours of enabling the new rule, it saved one of our customers from an intrusion that the stock rule missed,” Steve says.
SIEM developers rightfully talk a lot about their solutions’ machine learning capabilities. But the developers tend to focus their machine learning work on big customers, which means some of the tools don’t do much for small organizations generating a limited amount of monthly data. So Pratum’s analysts devote a lot of attention to modifying rule logic so that companies with, say, 30 employees benefit from the next-gen tools as much as companies with 1,000 employees.
For more information on how Pratum’s custom SIEM/XDR rules could make your organization more secure and efficient, contact us today.
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