Category Archives: backdoors

XZ Utils Backdoor

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The cybersecurity world got really lucky last week. An intentionally placed backdoor in XZ Utils, an open-source compression utility, was pretty much accidentally discovered by a Microsoft engineer—weeks before it would have been incorporated into both Debian and Red Hat Linux. From ArsTehnica:

Malicious code added to XZ Utils versions 5.6.0 and 5.6.1 modified the way the software functions. The backdoor manipulated sshd, the executable file used to make remote SSH connections. Anyone in possession of a predetermined encryption key could stash any code of their choice in an SSH login certificate, upload it, and execute it on the backdoored device. No one has actually seen code uploaded, so it’s not known what code the attacker planned to run. In theory, the code could allow for just about anything, including stealing encryption keys or installing malware…

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EU Court of Human Rights Rejects Encryption Backdoors

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The European Court of Human Rights has ruled that breaking end-to-end encryption by adding backdoors violates human rights:

Seemingly most critically, the [Russian] government told the ECHR that any intrusion on private lives resulting from decrypting messages was “necessary” to combat terrorism in a democratic society. To back up this claim, the government pointed to a 2017 terrorist attack that was “coordinated from abroad through secret chats via Telegram.” The government claimed that a second terrorist attack that year was prevented after the government discovered it was being coordinated through Telegram chats…

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New iPhone Exploit Uses Four Zero-Days

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Kaspersky researchers are detailing “an attack that over four years backdoored dozens if not thousands of iPhones, many of which belonged to employees of Moscow-based security firm Kaspersky.” It’s a zero-click exploit that makes use of four iPhone zero-days.

The most intriguing new detail is the targeting of the heretofore-unknown hardware feature, which proved to be pivotal to the Operation Triangulation campaign. A zero-day in the feature allowed the attackers to bypass advanced hardware-based memory protections designed to safeguard device system integrity even after an attacker gained the ability to tamper with memory of the underlying kernel. On most other platforms, once attackers successfully exploit a kernel vulnerability they have full control of the compromised system…

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Bounty to Recover NIST’s Elliptic Curve Seeds

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This is a fun challenge:

The NIST elliptic curves that power much of modern cryptography were generated in the late ’90s by hashing seeds provided by the NSA. How were the seeds generated? Rumor has it that they are in turn hashes of English sentences, but the person who picked them, Dr. Jerry Solinas, passed away in early 2023 leaving behind a cryptographic mystery, some conspiracy theories, and an historical password cracking challenge.

So there’s a $12K prize to recover the hash seeds.

Some backstory:

Some of the backstory here (it’s the funniest fucking backstory ever): it’s lately been circulating—though I think this may have been somewhat common knowledge among practitioners, though definitely not to me—that the “random” seeds for the NIST P-curves, generated in the 1990s by Jerry Solinas at NSA, were simply SHA1 hashes of some variation of the string “Give Jerry a raise”…

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Signal Will Leave the UK Rather Than Add a Backdoor

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Totally expected, but still good to hear:

Onstage at TechCrunch Disrupt 2023, Meredith Whittaker, the president of the Signal Foundation, which maintains the nonprofit Signal messaging app, reaffirmed that Signal would leave the U.K. if the country’s recently passed Online Safety Bill forced Signal to build “backdoors” into its end-to-end encryption.

“We would leave the U.K. or any jurisdiction if it came down to the choice between backdooring our encryption and betraying the people who count on us for privacy, or leaving,” Whittaker said. “And that’s never not true.”…

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New Revelations from the Snowden Documents

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Jake Appelbaum’s PhD thesis contains several new revelations from the classified NSA documents provided to journalists by Edward Snowden. Nothing major, but a few more tidbits.
Kind of amazing that that all happened ten years ago. At this point, … Continue reading New Revelations from the Snowden Documents→

Microsoft Signing Key Stolen by Chinese

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A bunch of networks, including US Government networks, have been hacked by the Chinese. The hackers used forged authentication tokens to access user email, using a stolen Microsoft Azure account consumer signing key. Congress wants answers. The phrase “negligent security practices” is being tossed about—and with good reason. Master signing keys are not supposed to be left around, waiting to be stolen.

Actually, two things went badly wrong here. The first is that Azure accepted an expired signing key, implying a vulnerability in whatever is supposed to check key validity. The second is that this key was supposed to remain in the the system’s Hardware Security Module—and not be in software. This implies a really serious breach of good security practice. The fact that Microsoft has not been forthcoming about the details of what happened tell me that the details are really bad…

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Backdoor in TETRA Police Radios

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Seems that there is a deliberate backdoor in the twenty-year-old TErrestrial Trunked RAdio (TETRA) standard used by police forces around the world.

The European Telecommunications Standards Institute (ETSI), an organization that standardizes technologies across the industry, first created TETRA in 1995. Since then, TETRA has been used in products, including radios, sold by Motorola, Airbus, and more. Crucially, TETRA is not open-source. Instead, it relies on what the researchers describe in their presentation slides as “secret, proprietary cryptography,” meaning it is typically difficult for outside experts to verify how secure the standard really is…

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Another Malware with Persistence

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Here’s a piece of Chinese malware that infects SonicWall security appliances and survives firmware updates.

On Thursday, security firm Mandiant published a report that said threat actors with a suspected nexus to China were engaged in a campaign to maintain long-term persistence by running malware on unpatched SonicWall SMA appliances. The campaign was notable for the ability of the malware to remain on the devices even after its firmware received new firmware.

“The attackers put significant effort into the stability and persistence of their tooling,” Mandiant researchers Daniel Lee, Stephen Eckels, and Ben Read wrote. “This allows their access to the network to persist through firmware updates and maintain a foothold on the network through the SonicWall Device.”…

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Putting Undetectable Backdoors in Machine Learning Models

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This is really interesting research from a few months ago:

Abstract: Given the computational cost and technical expertise required to train machine learning models, users may delegate the task of learning to a service provider. Delegation of learning has clear benefits, and at the same time raises serious concerns of trust. This work studies possible abuses of power by untrusted learners.We show how a malicious learner can plant an undetectable backdoor into a classifier. On the surface, such a backdoored classifier behaves normally, but in reality, the learner maintains a mechanism for changing the classification of any input, with only a slight perturbation. Importantly, without the appropriate “backdoor key,” the mechanism is hidden and cannot be detected by any computationally-bounded observer. We demonstrate two frameworks for planting undetectable backdoors, with incomparable guarantees…

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