WyzGuys Tech Talk

A quick Saturday digest of cybersecurity news articles from other sources.

Much of this content is from Bruce Schneier

Cell Phone Location Privacy

We all know that our cell phones constantly give our location away to our mobile network operators; that’s how they work. A group of researchers has figured out a way to fix that. “Pretty Good Phone Privacy” (PGPP) protects both user identity and user location using the existing cellular networks. It protects users from fake cell phone towers (IMSI-catchers) and surveillance by cell providers.

It’s a clever system. The players are the user, a traditional mobile network operator (MNO) like AT&T or Verizon, and a new mobile virtual network operator (MVNO). MVNOs aren’t new. They’re intermediaries like Cricket and Boost.

Here’s how it works:

1. One-time setup: The user’s phone gets a new SIM from the MVNO. All MVNO SIMs are identical.
2. Monthly: The user pays their bill to the MVNO (credit card or otherwise) and the phone gets anonymous authentication (using Chaum blind signatures) tokens for each time slice (e.g., hour) in the coming month.
3. Ongoing: When the phone talks to a tower (run by the MNO), it sends a token for the current time slice. This is relayed to a MVNO backend server, which checks the Chaum blind signature of the token. If it’s valid, the MVNO tells the MNO that the user is authenticated, and the user receives a temporary random ID and an IP address. (Again, this is now MVNOs like Boost already work.)
4. On demand: The user uses the phone normally.

The MNO doesn’t have to modify its system in any way. The PGPP MVNO implementation is in software. The user’s traffic is sent to the MVNO gateway and then out onto the Internet, potentially even using a VPN.

All connectivity is data connectivity in cell networks today. The user can choose to be data-only (e.g., use Signal for voice), or use the MVNO or a third party for VoIP service that will look just like normal telephony.

The group prototyped and tested everything with real phones in the lab. Their approach adds essentially zero latency, and doesn’t introduce any new bottlenecks, so it doesn’t have performance/scalability problems like most anonymity networks. The service could handle tens of millions of users on a single server, because it only has to do infrequent authentication, though for resilience you’d probably run more.

The paper is here.

Sophisticated Watering Hole Attack

Google’s Project Zero has exposed a sophisticated watering-hole attack targeting both Windows and Android:

Some of the exploits were zero-days, meaning they targeted vulnerabilities that at the time were unknown to Google, Microsoft, and most outside researchers (both companies have since patched the security flaws). The hackers delivered the exploits through watering-hole attacks, which compromise sites frequented by the targets of interest and lace the sites with code that installs malware on visitors’ devices. The boobytrapped sites made use of two exploit servers, one for Windows users and the other for users of Android

The use of zero-days and complex infrastructure isn’t in itself a sign of sophistication, but it does show above-average skill by a professional team of hackers. Combined with the robustness of the attack code — which chained together multiple exploits in an efficient manner — the campaign demonstrates it was carried out by a “highly sophisticated actor.”

The modularity of the payloads, the interchangeable exploit chains, and the logging, targeting, and maturity of the operation also set the campaign apart, the researcher said.

No attribution was made, but the list of countries likely to be behind this isn’t very large. If you were to ask me to guess based on available information, I would guess it was the US — specifically, the NSA. It shows a care and precision that it’s known for. But I have no actual evidence for that guess.

All the vulnerabilities were fixed by last April.

SVR Attacks on Microsoft 365

FireEye is reporting the current known tactics that the SVR used to compromise Microsoft 365 cloud data as part of its SolarWinds operation:

Mandiant has observed UNC2452 and other threat actors moving laterally to the Microsoft 365 cloud using a combination of four primary techniques:

• Steal the Active Directory Federation Services (AD FS) token-signing certificate and use it to forge tokens for arbitrary users (sometimes described as Golden SAML). This would allow the attacker to authenticate into a federated resource provider (such as Microsoft 365) as any user, without the need for that user’s password or their corresponding multi-factor authentication (MFA) mechanism.
• Modify or add trusted domains in Azure AD to add a new federated Identity Provider (IdP) that the attacker controls. This would allow the attacker to forge tokens for arbitrary users and has been described as an Azure AD backdoor.
• Compromise the credentials of on-premises user accounts that are synchronized to Microsoft 365 that have high privileged directory roles, such as Global Administrator or Application Administrator.
• Backdoor an existing Microsoft 365 application by adding a new application or service principal credential in order to use the legitimate permissions assigned to the application, such as the ability to read email, send email as an arbitrary user, access user calendars, etc.

Lots of details here, including information on remediation and hardening.

The more we learn about the this operation, the more sophisticated it becomes.

In related news, MalwareBytes was also targeted.

Insider Attack on Home Surveillance Systems

No one who reads this blog regularly will be surprised:

A former employee of prominent home security company ADT has admitted that he hacked into the surveillance feeds of dozens of customer homes, doing so primarily to spy on naked women or to leer at unsuspecting couples while they had sex.

[…]

Authorities say that the IT technician “took note of which homes had attractive women, then repeatedly logged into these customers’ accounts in order to view their footage for sexual gratification.” He did this by adding his personal email address to customer accounts, which ultimately hooked him into “real-time access to the video feeds from their homes.”

Slashdot thread.

Including Hackers in NATO Wargames

This essay makes the point that actual computer hackers would be a useful addition to NATO wargames:

The international information security community is filled with smart people who are not in a military structure, many of whom would be excited to pose as independent actors in any upcoming wargames. Including them would increase the reality of the game and the skills of the soldiers building and training on these networks. Hackers and cyberwar experts would demonstrate how industrial control systems such as power supply for refrigeration and temperature monitoring in vaccine production facilities are critical infrastructure; they’re easy targets and should be among NATO’s priorities at the moment.

Diversity of thought leads to better solutions. We in the information security community strongly support the involvement of acknowledged nonmilitary experts in the development and testing of future cyberwar scenarios. We are confident that independent experts, many of whom see sharing their skills as public service, would view participation in these cybergames as a challenge and an honor.

Medieval Security Techniques

Sonja Drummer describes (with photographs) two medieval security techniques. The first is a for authentication: a document has been cut in half with an irregular pattern, so that the two halves can be brought together to prove authenticity. The second is for integrity: hashed lines written above and below a block of text ensure that no one can add additional text at a later date.

Chinese Supply-Chain Attack on Computer Systems

Bloomberg News has a major story about the Chinese hacking computer motherboards made by Supermicro, Levono, and others. It’s been going on since at least 2008. The US government has known about it for almost as long, and has tried to keep the attack secret:

China’s exploitation of products made by Supermicro, as the U.S. company is known, has been under federal scrutiny for much of the past decade, according to 14 former law enforcement and intelligence officials familiar with the matter. That included an FBI counterintelligence investigation that began around 2012, when agents started monitoring the communications of a small group of Supermicro workers, using warrants obtained under the Foreign Intelligence Surveillance Act, or FISA, according to five of the officials.

There’s lots of detail in the article, and I recommend that you read it through.

This is a follow on, with a lot more detail, to a story Bloomberg reported on in fall 2018. I didn’t believe the story back then, writing:

I don’t think it’s real. Yes, it’s plausible. But first of all, if someone actually surreptitiously put malicious chips onto motherboards en masse, we would have seen a photo of the alleged chip already. And second, there are easier, more effective, and less obvious ways of adding backdoors to networking equipment.

I seem to have been wrong. From the current Bloomberg story:

Mike Quinn, a cybersecurity executive who served in senior roles at Cisco Systems Inc. and Microsoft Corp., said he was briefed about added chips on Supermicro motherboards by officials from the U.S. Air Force. Quinn was working for a company that was a potential bidder for Air Force contracts, and the officials wanted to ensure that any work would not include Supermicro equipment, he said. Bloomberg agreed not to specify when Quinn received the briefing or identify the company he was working for at the time.

“This wasn’t a case of a guy stealing a board and soldering a chip on in his hotel room; it was architected onto the final device,” Quinn said, recalling details provided by Air Force officials. The chip “was blended into the trace on a multilayered board,” he said.

“The attackers knew how that board was designed so it would pass” quality assurance tests, Quinn said.

Supply-chain attacks are the flavor of the moment, it seems. But they’re serious, and very hard to defend against in our deeply international IT industry. (I have repeatedly called this an “insurmountable problem.”) Here’s me in 2018:

Supply-chain security is an incredibly complex problem. US-only design and manufacturing isn’t an option; the tech world is far too internationally interdependent for that. We can’t trust anyone, yet we have no choice but to trust everyone. Our phones, computers, software and cloud systems are touched by citizens of dozens of different countries, any one of whom could subvert them at the demand of their government.

We need some fundamental security research here. I wrote this in 2019:

The other solution is to build a secure system, even though any of its parts can be subverted. This is what the former Deputy Director of National Intelligence Sue Gordon meant in April when she said about 5G, “You have to presume a dirty network.” Or more precisely, can we solve this by building trustworthy systems out of untrustworthy parts?

It sounds ridiculous on its face, but the Internet itself was a solution to a similar problem: a reliable network built out of unreliable parts. This was the result of decades of research. That research continues today, and it’s how we can have highly resilient distributed systems like Google’s network even though none of the individual components are particularly good. It’s also the philosophy behind much of the cybersecurity industry today: systems watching one another, looking for vulnerabilities and signs of attack.

It seems that supply-chain attacks are constantly in the news right now. That’s good. They’ve been a serious problem for a long time, and we need to take the threat seriously. For further reading, I strongly recommend this Atlantic Council report from last summer: “Breaking trust: Shades of crisis across an insecure software supply chain.“