What can we learn from the passwords used in brute-force attacks?

Thursday, May 2, 2024 14:00

Brute force attacks are one of the most elementary cyber threats out there. Technically, anyone with a keyboard and some free time could launch one of them — just try a bunch of different username and password combinations on the website of your choice until you get blocked.

Nick Biasini and I discussed some of the ways that organizations can defend against brute force attacks since detection usually doesn’t fall into the usual bucket (ex., there’s nothing an anti-virus program could detect running). But a good place to start just seems to be implementing strong password rules, because people, unsurprisingly, are still using some of the most obvious passwords that anyone, attacker or not, would guess.

Along with our advisory on a recent increase in brute force attacks targeting SSH and VPN services Cisco Talos published a list of IP addresses associated with this activity, along with a list of usernames and passwords adversaries typically try to use to gain access to a network or service.

There are some classics on this list — the ever-present “Password” password, Passw0rd (with a zero, not an “O”) and “123456.” This tells me that users still haven’t learned their lesson. It’s somewhat funny to think about some well-funded actor just being like, “Well, let me try to ‘hack’ into this machine by using ‘123456’” as if they’re in a parody movie, but if they already can guess a username based off someone’s real name, it’s not that unlikely that password is being used somewhere.

A few other example passwords stood out to me: “Mart1x21,” because I can’t tell if this is just someone named “Martin” or a play on the month of March, and things like “Spring2024x21” and “April2024x21” because I appreciate the idea that someone using that weak of a password thinks that adding the extra three characters onto “April2024” is really going to throw an attacker off.

Looking at this list got me thinking about what some potential solutions are to the internet’s password problem, and our ever-present battle to educate users and warn them about the dangers of using weak or default passwords.

Going passwordless is certainly one option because if there just are no passwords to log in, there’s nothing text-based an attacker could just start guessing.

The best solution I’ve seen recently is that the U.K. literally made a law requiring hardware and software manufacturers to implement stronger security standards. The Product Security and Telecommunications Infrastructure (PSTI) that went into effect last month contains a range of security protections companies must follow, but they now include mandatory password rules that will force users to change default passwords when registering for new accounts and stop them from using easy-to-guess passwords like “Admin” and “12345.”

It would be great if users would just stop using these credentials on their own, but if attackers are still thinking that someone out there is using “Password” as their password, they probably are.

**The one big thing **

For the first time in several quarters, business email compromise (BEC) was the most common threat in Cisco Talos Incident Response (Talos IR) engagements during the first quarter of 2024. BEC made up 46 percent of all engagements in Q1, a significant spike from Q4 2023, according to the latest Talos IR Quarterly Trends Report. Ransomware, which was the top-observed threat in the last quarter of 2023, decreased by 11 percent. Talos IR also observed a variety of threats in engagements, including data theft extortion, brute-force activity targeting VPNs, and the previously seen commodity loader Gootloader.

**Why do I care? **

BEC is a tactic adversaries use to disguise themselves as legitimate members of a business and send phishing emails to other employees or third parties, often pointing to a malicious payload or engineering a scheme to steal money. The use of email-hiding inbox rules was the top-observed defense evasion technique, accounting for 21 percent of engagements this quarter, which was likely due to an increase in BEC and phishing within engagements. These are all valuable insights from the field provided in Talos IR’s full report.

**So now what? **

There are some known indicators of compromise that customers can look for if they suspect The lack of MFA remains one of the biggest impediments for enterprise security. All organizations should implement some form of MFA, such as Cisco Duo. The implementation of MFA and a single sign-on system can ensure only trusted parties are accessing corporate email accounts, to prevent the spread of BEC. If you’d like to read about other lessons from recent Talos IR engagements, read the one-pager here or the blog post here.

**Top security headlines of the week **

The chief executive of UnitedHealth Group testified to U.S. Congress on Wednesday regarding the recent cyber attack against Change Healthcare. Change’s operations went nearly completely dark for weeks earlier this year after a data breach, which likely resulted in millions of patients’ records and personal information being accessed. Lawmakers questioned whether UnitedHealth was too involved in the nation’s medical systems, as Change manages a third of all American patient records and processes more than 15 billion transactions a year at doctor’s offices, hospitals and other medical providers. As a result of the outage, some healthcare practitioners went more than a month without being paid, and many had to tap into their personal funds to keep offices open. UnitedHealth’s CEO told Congress the company was still working to figure out the full extent of the campaign and was talking to U.S. agencies about how to best notify individuals who were affected. The hearing has also generated a conversation around consolidation in the American healthcare industry and whether some groups are controlling too much of the patient base. (The New York Times, CNBC)

Vulnerabilities in a popular phone tracking app could allow anyone to view all users’ locations. A security researcher recently found that iSharing, which allows users to see the exact location of a device, contains a vulnerability that prevented the app’s servers from conducting proper checks of user data access. iSharing is advertised as an app for users who want to track friends’ and family members’ locations or as an extra layer of security if their device were to be lost or stolen. The flaws also exposed users’ names, profile pictures, email addresses and phone numbers. The researcher who discovered the vulnerability was able to show a proof-of-concept exploitation almost immediately after creating a brand new account on the app. Representatives from the developers of iSharing told TechCrunch that the company’s logs did not show any signs of the vulnerability being exploited prior to the researcher’s disclosure. These types of apps can also be used as “stalkerware,” in which someone who knows a targeted user quietly downloads the app on a target’s phone, and then uses it to remotely track their location. (TechCrunch)

Adversaries are hiding malware in GitHub comments, disguising malicious code as URLs associated with Microsoft repositories, and making the files appear trustworthy. Although some security researchers view this as a vulnerability, Microsoft maintains that it is merely a feature of using GitHub. While adversaries have so far mainly abused this feature to mirror Microsoft URLs, it could theoretically be used to create convincing lures on any GitHub repository. When a user leaves a comment in GitHub, they can attach a file, which is then uploaded to GitHub’s CDN and associated with the related project using a unique URL. GitHub automatically generates the link to download that attachment after adding the file to an unsaved comment, allowing threat actors to attach malware to any repository without the administrators knowing. This method has already been abused to distribute the Readline information-stealing trojan by attaching comments to Microsoft’s GitHub-hosted repositories for “vcpkg” and “STL.” The malicious URL will even still work if the poster deletes the comment, allowing them to reuse the GitHub-generated URL. (Bleeping Computer, Dark Reading)

**Can’t get enough Talos? **

• Cisco Talos at RSAC 2024
• Cisco Zero-Days Anchor ‘ArcaneDoor’ Cyber-Espionage Campaign
• Governments issue alerts after ‘sophisticated’ state-backed actor found exploiting flaws in Cisco security boxes
• Vulnerabilities in employee management system could lead to remote code execution, login credential theft
• Researcher Spotlight: James Nutland studies what makes threat actors tick, growing our understanding of the current APT landscape

Upcoming events where you can find Talos

RSA (May 6 - 9)

San Francisco, California

ISC2 SECURE Europe (May 29)

Amsterdam, Netherlands

Gergana Karadzhova-Dangela from Cisco Talos Incident Response will participate in a panel on “Using ECSF to Reduce the Cybersecurity Workforce and Skills Gap in the EU.” Karadzhova-Dangela participated in the creation of the EU cybersecurity framework, and will discuss how Cisco has used it for several of its internal initiatives as a way to recruit and hire new talent.

Cisco Live (June 2 - 6)

Las Vegas, Nevada

**Most prevalent malware files from Talos telemetry over the past week **

This section will be on a brief hiatus while we work through some technical difficulties.