Defense Techniques: Reporting Phish

While I have a day job, I’ve been moonlighting as a crimefighting superhero for almost twenty years. No, I’m not a billionaire who dons a rubber bat suit to beat up bad guys– I’m instead flagging phishing websites that try to steal money and personal information from the less tech-savvy among us.

I have had a Hotmail account for over twenty-five years now, and I get a LOT of phishing emails there– at least a few every day. This account turns out to be a great source of real-world threats– the bad guys are (unknowingly) prowling around a police station with lockpicks and crowbars.

Step 1: Report the Lure Email

When I get a phishing email, I first forward it to Netcraft (scam@netcraft.com) and PhishTank. I copy the URL from the lure, then use the Report > Report Phishing option in Outlook to report the phish to Microsoft:

Step 2: Additional Research

If I have time, I’ll go look up the URL on URLScan.io and/or VirusTotal to see what they have to say, before loading it into my browser.

Step 3: Load & Report the Phishing Site

Now, most sources will instruct you to never click on a phishing link and this is, in general, great advice. The primary concern is that an attacker might not just be phishing– they might try to exploit a 0-day in your browser to compromise your PC. This is a legitimate concern, but there are ways to mitigate that risk: only use a fully-patched browser, use a Guest profile to mitigate the risk of ambient credential abuse, ensure that you’ve got Enhanced Security mode enabled to block JIT-reliant attacks, and if you’re very concerned, browse using Microsoft Defender AppGuard.

If the phishing site loads (and is not already down or blocked), I then report it to SmartScreen via the ... > Help and feedback > Report unsafe site menu command:

I also report the phishing site to Google’s Chrome/SafeBrowsing team using the Suspicious Site Reporter extension. This extension allows tech-savvy users to recognize suspicious signals for sites they visit and report malicious sites to SafeBrowsing in a single click:

Importantly, the report doesn’t just contain the malicious URL– it also contains information like the Referrer Chain (the list of URLs that caused the malicious page to load), and a Screenshot of the current page (useful for combatting cloaking).

Attacker Technique: Cloaking from Graders

When a user reports a site as phishing, the report typically is sent to a human grader who evaluates the report to determine whether it’s legitimate. The grader typically will load the reported URL to see whether the target meets the criteria for phishing (e.g. is it asking for credentials or credit card numbers and impersonating a legitimate site?).

Phishers do not like it when their websites get blocked quickly.

A technique they use to keep their sites alive longer is named “cloaking.” This technique relies upon detecting that their site has been loaded not by a victim but instead by a grader, and if so, playing innocent– either by returning a generic 404, or by redirecting to some harmless page.

Phishers have many different strategies for detecting graders, including:

  • recognizing known IP ranges (e.g. “If I’m being loaded from an IP block known to be used by Google or Microsoft Corp, I’m probably being graded“)
  • single-use URLs (e.g. put a token in the URL and if that token is seen more than once, play innocent)
  • geo-targeted phish (e.g. “If I’m phishing a UK bank, but the user’s IP is not in the UK, play innocent”)
  • fingerprinting the user’s browser to determine how likely it is that it’s a potential victim

Some phishing sites are hosted unintentionally. In these cases, a server is owned by a legitimate company, but bad guys find a way to plant content on that server such that it is only shown to specific, targeted victims. For example, over a decade ago, I received report of an unblocked phishing webpage that was hosted by a hockey rink owner in the US Midwest. My investigation revealed that American visitors to the site would get a normal hockey team signup webpage. However, the phishing campaign was targeting a Russian bank, and if the user visited the site using a browser sending an Accept-Language: ru request header indicating that they spoke Russian, the site would instead serve phishing content. English-speaking graders would never be able to “see” the attack without knowing the “secret” that the site was using to decide whether to serve phishing content. Without screenshots of what a victim sees, graders have a very hard time deciding whether a given False Negative report is accurate or not.

Cloaking makes the job of a grader much harder– even if the reporter can go back to the grader with additional evidence, the delay in doing so could be hours, which is often the upper-limit of a phishing site’s lifetime anyway.

This Coinbase-phish cloaks by redirecting graders to the real Coinbase

Additional Options

If you want to learn even more ways to combat phishing sites, check out the guide at GotPhish.com.

For example, Netcraft also offers a browser extension that shows data about the current website and allows easy reporting of phish:

If doing a good deed isn’t enough, Netcraft also offers some fun incentives for phishing reports— so far, I’ve collected the flash drive, mug, and t-shirt.

Tiered Defenses: Experts as Canaries

One criticism against adding advanced features to browsers to allow analysis or recognition of phishing sites is that the vast majority of users will not be able to make effective use of them. For instance, features like domain highlighting (showing the eTLD+1 in bold text) are meaningless to 99% of users.

But critically, such cues and signals like these are useful to experts, who can recognize the signs of a phish and “pull the alarm” to report phishing sites to SmartScreen, SafeBrowsing, and other threat intel services.

These threat reports, consumed by threat intelligence services, then scale up to “protect the herd.” Browsers’ blocking pages for known phish are demonstrably extremely effective, with high adherence even by novice users.

Making a Difference

Now, it’s easy to wonder whether or not any of this end-user reporting matters — there are millions of new phish a week — can reporting one make a difference?

Beyond my immediate answer (yes), I have personal evidence of the impact. One of my happiest memories of working on the IE team was when the SmartScreen team looked up how many potential victims my phish reports blocked. I shared with them my private reporter ID and they looked up my phishing reports in the backend, then cross-referenced how many phishing blocks resulted from those reports. The number was well into the thousands.

Beyond the immediate blocks, threat reports these days are also used by researchers to identify phishing toolkits and campaigns, and new techniques phishers are adopting. Threat reports are fed into AI/ML models and used to train automatic detection of future campaigns, making the life of phishers more difficult and less profitable.

Thanks for your help in protecting everyone!

-Eric

SlickRun

While I’m best known for creating Fiddler two decades ago, eight years before Fiddler’s debut I started work on what became SlickRun. SlickRun is a floating command line that provides nearly instant access to almost any app or website. Originally written in Visual Basic 3 and released as QuickRun for Windows 3.1, it was soon ported to Borland Delphi and later renamed SlickRun to avoid a name-collision with an unrelated tool.

SlickRun was a part of the story of how I joined Microsoft — when I had my on-campus interview for my first internship, I’d brought a binder of screenshots from apps that I’d written. My interviewer was generally interested but got super-excited as I explained what SlickRun did. “Have you shown this to Microsoft??” he asked. Flummoxed and wondering Uh, how exactly would I have done that?, I replied “Uh, I guess I just did?” Five years later when I interviewed for the IE team, the GM interviewing me asked “How often do you type www.goo in the browser address bar and wish it did the right thing?” to which I responded “Uh, less than you might think.” before showing off the autocomplete inside SlickRun. I got that job too.

While I’ve maintained SlickRun routinely over the years, making updates as needed to support 32bit, and then 64bit Windows, and keep it compatible with new paradigms in Windows Vista and beyond, I’ve done relatively little to publicize it to the world at large. It just quietly hums along with a mostly-satisfied userbase of thousands around the world.

Personally, I’ve been using SlickRun nearly daily for almost three decades and have executed almost 200000 commands on my latest fleet of Windows 11 PCs.

Perhaps the biggest problem with SlickRun is that, designed to be small and simple, it offers few affordances to reveal the tremendous amount of power living under the surface. By default, it ships with only a handful of MagicWords (command shortcuts/aliases) but it will never achieve its full power unless the user creates their own MagicWords to match their own needs and terminology.

If a user types HELP, an online help page will open to explain the basics, and for the few who bother to read that page, an advanced usage page reveals some even less obvious features of the tool.

I’ve been meaning to put together a demo reel video for decades now but have never gotten around to it. Mostly, SlickRun has spread organically, with folks seeing it in use on a peer’s desktop and asking “Hey, how … what is that?”

Idle Info Display

Beyond its program-launching features, SlickRun provides a useful little perch for showing information in an always-visible (by default) location on your desktop. If you type SETUP, there’s a variety of display customization options. SlickRun’s “idle” appearance which can show useful things like clocks (in arbitrary time zones), date, battery life, days-until-an-event, machine name, IP address, memory usage, CPU usage, etc:

If SlickRun ever gets in your way (e.g. while watching a full-screen video), just type HIDE to tell it to hide out in your system tray until summoned.

The Basics

Click on SlickRun or hit the hotkey to activate it and enter command mode. (The hotkey is configurable via SETUP. For historical reasons, it defaults to Win+Q which doesn’t work on modern Windows without a simple registry modification due to other tools camping on that key. After a decade, I configured mine to Alt+Q instead.)

Type a command into SlickRun and hit enter to launch it. You can hit the tab key to jump to the end of an autocomplete suggestion if you want to change or add arguments at the end of the command.

Use the up/down arrow keys to scroll through your command history– if you’ve already typed some characters, the history is filtered to just the commands that match. Or hit Alt+F to show a context menu list of all matches (or ALT+Shift+F to loosen the matching to the entire command, not just the prefix). Or, hit Alt+S to show a context menu list containing any Start Menu shortcuts containing what you’ve already typed.

SlickRun loves the internet. Type a url in SlickRun to open it in your default browser. My very favorite MagicWord launches an “I’m Feeling Lucky” Search on Google, so I can type goto SlickRun and https://bayden.com/slickrun/ will open (see this post for more info). This works magically well.

As you can see, you can add MagicWords to launch web searches, where $W$ is filled by a URL-encoded parameter. For example:

After creating this MagicWord, you can type errors 0x1234 and your browser will go to the relevant URL. If you fail to specify a parameter when invoking the MagicWord, you’ll be asked to supply it via a popup window:

You can type CALENDAR to launch a calendar, or CALENDAR 5/6 to jump to May sixth.

Using @MULTI@, you can have a single MagicWord launch multiple commands:

In cases where you have related commands, you can name your MagicWords with a slash in the middle of them; each tab of the tab key will jump to the next slash, allowing you to adjust what is autocompleted as you go.

So, for example, I can type e.g. e{tab}s to get to “Edge Stable” in the autocomplete:

When executing a MagicWord, a $C$ token will replaced by any text found on the clipboard.

Hit Ctrl+I to get a Windows file picker to insert a file path at the current location of the command line string. Or, tap Ctrl+V with one or more files on your clipboard and SlickRun will insert the file path(s) at the current insertion point. Hit Ctrl+T to transpose the last two arguments in the current command (e.g. windiff A B becomes windiff B A) and hit CTRL+\ to convert any Unix-style path separator backslashes (c/src/chrome/) into Windows-style backslashes (c\src\chrome\).

SlickRun can perform simple math operations, with the answer output inline such that you can chain it to a subsequent operation. Try things like

=2^9
=SQR(100)
=123*456
=0x123
=HEX(123)

When running a command, use Shift+Enter to execute a command that should be immediately forgotten. Use Ctrl+Shift+Enter to execute a command elevated (as administrator).

You can create a MagicWord named _a which will execute any time you hit ALT+Enter to submit a command, so the following MagicWord allows you to look up a word by typing define powerful or ?powerful or just typing powerful and submitting via Alt+Enter:

If you name your MagicWord _default, SlickRun will execute it if no other command is found.

Automatic Behaviors

You can use SETUP to configure an hourly chime with an optional offset so you’ll have a minute or more to get ready for your next meeting or appointment:

A MagicWord named _STARTUP will be run automatically anytime SlickRun starts. A MagicWord named _DISPLAYCHANGE will run automatically anytime your Windows display resolution changes.

SlickRun flashes when your clipboard is updated, useful for confirming that your attempt to copy something from another app was successful.

Clipboard & Drag/Drop

You can create a MagicWord with the @copy@ command to copy a string to your clipboard, useful if you have a string that you need to use frequently.

You can drag/drop URLs from webpages, or icons from Start/Desktop to create MagicWords pointing to them.

Hit Ctrl+V with one or more files on your clipboard and SlickRun will insert the file path(s) at the current insertion point.

You can drag/drop text from anywhere to SlickRun to add it to your JOT, an auto-saving jotpad, useful for recording addresses, phone numbers, order confirmation numbers, and the like. Type JOT to reopen it later.

Shortcomings

Every tool has its limits, and SlickRun is no exception. There are a bunch of features that I’d like to add, but I haven’t gotten around to over the decades.

The most often noticed shortcoming is that SlickRun doesn’t offer roaming for features you’d hope (in particular, the MagicWord list and the text of the JOT). Unfortunately, it’s non-trivial, and while you can import/export your command library, you cannot trivially use OneDrive or Google Drive to keep a single command library in sync.

I’ve always daydreamed about adding “natural” language recognition to SlickRun (including voice recognition) but I’ve never made any significant effort to explore it, even as technology has advanced to the point where doing so might now be very practical. (LLVMs like ChatGPT are an obvious integration).

SlickRun should be open-source, but the code is in a language (Delphi/Object Pascal) which is uncommon. While the code works, it’s not of quality that I would be proud for anyone to see. In the early years, I had a collaborator who wrote the performance critical auto-complete logic, but in twenty years since, only I have lain eyes on SlickRun’s mostly crusty code. I periodically ponder an OSS rewrite in C# (someone else did this as a short-lived project named “MagicWords”) but haven’t found the energy. Fiddler users might recognize that tool’s QuickExec box‘s origins in SlickRun– I partly added QuickExec to Fiddler in the hopes that one day I’d find that I’d added so much functionality to it that I could fork that code out into a SlickRun.NET. Alas, that didn’t happen by the time Telerik acquired Fiddler.

I hope you find SlickRun useful!

-Eric

2022 EOY Fitness Summary

I spent dramatically more time on physical fitness in 2022 than I have at any other point in my life, in preparation for my planned adventure this June.

My 2022 statistics from iFit on my incline trainer/treadmill show that I walked/jogged/ran almost 700 miles after it was set up on January 24th:

Perhaps surprisingly (given the summer heat), I got the most miles in over the summer months:

Beyond the treadmill, I also ran a few real-world races. Compared to the first half, my use of the exercise bike declined in the latter half of the year, but I still rode a few times a month:

I ended the year 52.7 pounds lighter than I started it, bottoming out at 178.4 pounds in early September before rebounding a bit in the final months of the year. My estimated body fat percentage dropped from a peak of 28.9% to just under 15%.

My FitBit reports 4,186,894 steps, 3184 floors, 2181.91 miles and 1,183,581 calories burned:

My resting heart rate dropped from 64 to 54 beats per minute in the first third of the year, and has bounced around by a beat or two over the rest of the year. I haven’t checked my blood pressure regularly since noting a big improvement in the first third of the year. I got my fourth COVID shot before a second COVID infection in September– I shrugged it off easily in a week.

Looking forward

I’ve got a real-world half marathon (3M) coming up in just over a week, then the Austin Capital 10K coming in April. Then, hiking Kilimanjaro in June.

After that, I’m not sure what’s next: right now, I expect to cut back on running distances to stay around 10Ks, and hope I’ll be able to force myself to start using the rower regularly.

I’m doing another “Dry January” this year. My experiment with alcohol-free beer (Athletic Brewing Company) is a mixed bag– it tastes “fine“, but triggers the same munchies that “real” beer does, which rather limits the point of the exercise. I tried an alcohol-free liquor (“Spirit of Milano“) but I really don’t like it– I’ll stick to cranberry juice.

Attack Techniques: Priming Attacks on Legitimate Sites

Earlier today, we looked at two techniques for attackers to evade anti-phishing filters by using lures that are not served from http and https urls that are subject to reputation analysis.

A third attack technique is to send a lure that entices a user to visit a legitimate site and perform an unsafe operation on that site. In such an attack, the phisher never collects the user’s password directly, and because the brunt of the attack occurs while on the legitimate site, anti-phishing filters typically have no way to block the attacks. I will present three examples of such attacks in this post.

“Consent Phishing”

In the first example, the attacker sends their target an email containing lure text that entices the user to click a link in the email:

The attacker controls the text of the email and can thus prime the user to make an unsafe decision on the legitimate site, which the attacker does not control. In this case, clicking the link brings the victim to an account configuration page. If the user is prompted for credentials when clicking the link, the credentials are collected on the legitimate site (not a phishing URL), so anti-phishing filters have nothing to block.

The attacker has very limited control over the contents of the account config page, but thanks to priming, the user is likely to make a bad decision, unknowingly granting the attacker access to the content of their account:

A malicious app whose OAuth prompt shows a misleading name (“Outlook Mail”) and icon

If access is granted, the attacker has the ability to act “as the user” when it comes to their email. Beyond sensitive content within the user’s email account, most sites offer password recovery options bound to an email address, and after compromising the user’s email account the attacker can likely pivot to attack their credentials on other sites.

This technique isn’t limited to Microsoft accounts, as demonstrated by this similar attack against Google:

… and this recent campaign against users of Salesforce.

“Invoice Scam”

A second example is a long-running attack via sites like PayPal. PayPal allows people to send requests for money to one another, with content controlled by the attacker. In this case, the lure is sent by PayPal itself. As you can see, Outlook even notes that “This message is from a trusted sender” without the important caveat that the email also contains untrusted and inaccurate content authored by a malicious party.

A victim encountering this email may respond in one of two ways. First, they might pick up the phone and call the phone number provided by the attacker, and the attack would then continue via telephone– because the attack is now “offline”, anti-phishing filters will not get in the way.

Alternatively, a victim encountering the email might click on the link, which brings them to the legitimate PayPal website. Anti-phishing filters have nothing to say here, since the victim has been directed to the legitimate site (albeit with dangerous parameters). Perhaps alarmingly, PayPal has decided to “reduce friction” and automatically trust devices you’ve previously used, meaning that users might not even prompted for a password when clicking through the link:

Misleading trust indicators and the desire for simple transactions mean that a user is just clicks away from losing hundreds of dollars to an attacker.

“Malicious Extensions”

In the final example of a priming attack, a malicious website can trick the user into installing a malicious browser extension. This is often positioned as a security check, and often uses assorted trickery to try to prevent the user from recognizing what’s happening, including sizing and positioning the Web Store window in ways to try to obscure important information. Google explicitly bans such conduct in their policy:

… but technical enforcement is more challenging.

Because the extension is hosted and delivered by the “official” web store, the browser’s security restrictions and anti-malware filters are not triggered.

After a victim installs a malicious browser extension, the extension can hijack their searches, spam notifications, steal personal information, or embark upon other attacks until such time as the extension is recognized as malicious by the store and nuked from orbit.

Best Practices

When building web experiences, it’s important that you consider the effect of priming — an attacker can structure lures to confuse a user and potentially misunderstand a choice offered by your website. Any flow that offers the user a security choice should have a simple and unambiguous option for users to report “I think I’m being scammed“, allowing you to take action against abuse of your service and protect your customers.

If you’re an Entra administrator, you can configure your tenant to restrict individual users from granting consent to applications:

-Eric

Attack Techniques: Phishing via Mailto

Earlier today, we looked at a technique where a phisher serves his attack from the user’s own computer so that anti-phishing code like SmartScreen and SafeBrowsing do not have a meaningful URL to block.

A similar technique is to encode the attack within a mailto URL, because anti-phishing scanners and email clients rarely apply reputation intelligence to the addressee of outbound email.

In this attack, the phisher’s lure email contains a link which points at a URL that uses the mailto: scheme to construct a reply email:

A victim who falls for this attack and clicks the link will find that their email client opens with a new message with a subject of the attacker’s choice, addressed to the attacker, possibly containing pre-populated body text that requests personal information. Alternatively, the user might just respond by sending a message saying “Hey, please protect me” or the like, and the attacker, upon receipt of the reply email, can then socially-engineer personal information out of the victim in subsequent replies.

The even lazier variant of this attack is to simply email the victim directly and request that they provide all of their personal information in a reply:

While this version of the attack feels even less believable, victims still fall for the scam, and there are even logical reasons for scammers to target only the most credulous victims.

Notably, while mail-based attacks might solicit the user’s credentials information, they might not even bother, instead directly asking for other monetizable information like credit card or banking numbers.

-Eric