Entries Tagged "tamper detection"

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Detecting Deepfake Picture Editing

“Markpainting” is a clever technique to watermark photos in such a way that makes it easier to detect ML-based manipulation:

An image owner can modify their image in subtle ways which are not themselves very visible, but will sabotage any attempt to inpaint it by adding visible information determined in advance by the markpainter.

One application is tamper-resistant marks. For example, a photo agency that makes stock photos available on its website with copyright watermarks can markpaint them in such a way that anyone using common editing software to remove a watermark will fail; the copyright mark will be markpainted right back. So watermarks can be made a lot more robust.

Here’s the paper: “Markpainting: Adversarial Machine Learning Meets Inpainting,” by David Khachaturov, Ilia Shumailov, Yiren Zhao, Nicolas Papernot, and Ross Anderson.

Abstract: Inpainting is a learned interpolation technique that is based on generative modeling and used to populate masked or missing pieces in an image; it has wide applications in picture editing and retouching. Recently, inpainting started being used for watermark removal, raising concerns. In this paper we study how to manipulate it using our markpainting technique. First, we show how an image owner with access to an inpainting model can augment their image in such a way that any attempt to edit it using that model will add arbitrary visible information. We find that we can target multiple different models simultaneously with our technique. This can be designed to reconstitute a watermark if the editor had been trying to remove it. Second, we show that our markpainting technique is transferable to models that have different architectures or were trained on different datasets, so watermarks created using it are difficult for adversaries to remove. Markpainting is novel and can be used as a manipulation alarm that becomes visible in the event of inpainting.

Posted on June 10, 2021 at 6:19 AM • View Comments

More SolarWinds News

Microsoft analyzed details of the SolarWinds attack:

Microsoft and FireEye only detected the Sunburst or Solorigate malware in December, but Crowdstrike reported this month that another related piece of malware, Sunspot, was deployed in September 2019, at the time hackers breached SolarWinds’ internal network. Other related malware includes Teardrop aka Raindrop.

Details are in the Microsoft blog:

We have published our in-depth analysis of the Solorigate backdoor malware (also referred to as SUNBURST by FireEye), the compromised DLL that was deployed on networks as part of SolarWinds products, that allowed attackers to gain backdoor access to affected devices. We have also detailed the hands-on-keyboard techniques that attackers employed on compromised endpoints using a powerful second-stage payload, one of several custom Cobalt Strike loaders, including the loader dubbed TEARDROP by FireEye and a variant named Raindrop by Symantec.

One missing link in the complex Solorigate attack chain is the handover from the Solorigate DLL backdoor to the Cobalt Strike loader. Our investigations show that the attackers went out of their way to ensure that these two components are separated as much as possible to evade detection. This blog provides details about this handover based on a limited number of cases where this process occurred. To uncover these cases, we used the powerful, cross-domain optics of Microsoft 365 Defender to gain visibility across the entire attack chain in one complete and consolidated view.

This is all important, because MalwareBytes was penetrated through Office 365, and not SolarWinds. New estimates are that 30% of the SolarWinds victims didn’t use SolarWinds:

Many of the attacks gained initial footholds by password spraying to compromise individual email accounts at targeted organizations. Once the attackers had that initial foothold, they used a variety of complex privilege escalation and authentication attacks to exploit flaws in Microsoft’s cloud services. Another of the Advanced Persistent Threat (APT)’s targets, security firm CrowdStrike, said the attacker tried unsuccessfully to read its email by leveraging a compromised account of a Microsoft reseller the firm had worked with.

On attribution: Earlier this month, the US government has stated the attack is “likely Russian in origin.” This echos what then Secretary of State Mike Pompeo said in December, and the Washington Post‘s reporting (both from December). (The New York Times has repeated this attribution—a good article that also discusses the magnitude of the attack.) More evidence comes from code forensics, which links it to Turla, another Russian threat actor.

And lastly, a long ProPublica story on an unused piece of government-developed tech that might have caught the supply-chain attack much earlier:

The in-toto system requires software vendors to map out their process for assembling computer code that will be sent to customers, and it records what’s done at each step along the way. It then verifies electronically that no hacker has inserted something in between steps. Immediately before installation, a pre-installed tool automatically runs a final check to make sure that what the customer received matches the final product the software vendor generated for delivery, confirming that it wasn’t tampered with in transit.

I don’t want to hype this defense too much without knowing a lot more, but I like the approach of verifying the software build process.

Posted on February 3, 2021 at 6:10 AM • View Comments

Maliciously Tampering with Medical Imagery

In what I am sure is only a first in many similar demonstrations, researchers are able to add or remove cancer signs from CT scans. The results easily fool radiologists.

I don’t think the medical device industry has thought at all about data integrity and authentication issues. In a world where sensor data of all kinds is undetectably manipulatable, they’re going to have to start.

Research paper. Slashdot thread.

Posted on April 12, 2019 at 11:13 AM • View Comments

Computer Alarm that Triggers When Lid Is Opened

“Do Not Disturb” is a Macintosh app that send an alert when the lid is opened. The idea is to detect computer tampering.

Wired article:

Do Not Disturb goes a step further than just the push notification. Using the Do Not Disturb iOS app, a notified user can send themselves a picture snapped with the laptop’s webcam to catch the perpetrator in the act, or they can shut down the computer remotely. The app can also be configured to take more custom actions like sending an email, recording screen activity, and keeping logs of commands executed on the machine.

Can someone please make one of these for Windows?

Posted on April 24, 2018 at 6:04 AM • View Comments

Jackpotting Attacks Against US ATMs

Brian Krebs is reporting sophisticated jackpotting attacks against US ATMs. The attacker gains physical access to the ATM, plants malware using specialized electronics, and then later returns and forces the machine to dispense all the cash it has inside.

The Secret Service alert explains that the attackers typically use an endoscope—a slender, flexible instrument traditionally used in medicine to give physicians a look inside the human body—to locate the internal portion of the cash machine where they can attach a cord that allows them to sync their laptop with the ATM’s computer.

“Once this is complete, the ATM is controlled by the fraudsters and the ATM will appear Out of Service to potential customers,” reads the confidential Secret Service alert.

At this point, the crook(s) installing the malware will contact co-conspirators who can remotely control the ATMs and force the machines to dispense cash.

“In previous Ploutus.D attacks, the ATM continuously dispensed at a rate of 40 bills every 23 seconds,” the alert continues. Once the dispense cycle starts, the only way to stop it is to press cancel on the keypad. Otherwise, the machine is completely emptied of cash, according to the alert.

Lots of details in the article.

Posted on February 1, 2018 at 6:23 AM • View Comments

Tamper-Detection App for Android

Edward Snowden and Nathan Freitas have created an Android app that detects when it’s being tampered with. The basic idea is to put the app on a second phone and put the app on or near something important, like your laptop. The app can then text you—and also record audio and video—when something happens around it: when it’s moved, when the lighting changes, and so on. This gives you some protection against the “evil maid attack” against laptops.

Micah Lee has a good article about the app, including some caveats about its use and security.

Posted on January 3, 2018 at 6:17 AM • View Comments

Tainted Leaks

Last year, I wrote about the potential for doxers to alter documents before they leaked them. It was a theoretical threat when I wrote it, but now Citizen Lab has documented this technique in the wild:

This report describes an extensive Russia-linked phishing and disinformation campaign. It provides evidence of how documents stolen from a prominent journalist and critic of Russia was tampered with and then “leaked” to achieve specific propaganda aims. We name this technique “tainted leaks.” The report illustrates how the twin strategies of phishing and tainted leaks are sometimes used in combination to infiltrate civil society targets, and to seed mistrust and disinformation. It also illustrates how domestic considerations, specifically concerns about regime security, can motivate espionage operations, particularly those targeting civil society.

Posted on May 29, 2017 at 10:22 AM • View Comments

Defeating a Tamper-Proof Bottle

Here’s an interesting case of doctored urine-test samples from the Sochi Olympics. Evidence points to someone defeating the tamper resistance of the bottles:

Berlinger bottles come in sets of two: one for the athlete’s “A” sample, which is tested at the Games, and the other for the “B” sample, which is used to corroborate a positive test of the A sample. Metal teeth in the B bottle’s cap lock in place, so it cannot be twisted off.

“The bottles are either destroyed or retain visible traces of tampering if any unauthorized attempt is made to open them,” Berlinger’s website says about the security of the bottles.

The only way to open the bottle, according to Berlinger, is to use a special machine sold by the company for about $2,000; it cracks the bottle’s cap in half, making it apparent that the sample has been touched.

Yet someone figured out how to open the bottles, swap out the liquid, and replace the caps without leaving any visible signs of tampering.

EDITED TO ADD: There’s a new article on how they did it.

In Room 124, Dr. Rodchenkov received the sealed bottles through the hole and handed them to a man who he believed was a Russian intelligence officer. The man took the bottles to a building nearby. Within a few hours, the bottles were returned with the caps loose and unbroken.

One commenter complained that I called the bottles “tamper-proof,” even though I used the more accurate phrase “tamper-resistance” in the post. Yes, that was sloppy.

Posted on May 16, 2016 at 6:03 AM • View Comments

Surreptitiously Tampering with Computer Chips

This is really interesting research: “Stealthy Dopant-Level Hardware Trojans.” Basically, you can tamper with a logic gate to be either stuck-on or stuck-off by changing the doping of one transistor. This sort of sabotage is undetectable by functional testing or optical inspection. And it can be done at mask generation—very late in the design process—since it does not require adding circuits, changing the circuit layout, or anything else. All this makes it really hard to detect.

The paper talks about several uses for this type of sabotage, but the most interesting—and devastating—is to modify a chip’s random number generator. This technique could, for example, reduce the amount of entropy in Intel’s hardware random number generator from 128 bits to 32 bits. This could be done without triggering any of the built-in self-tests, without disabling any of the built-in self-tests, and without failing any randomness tests.

I have no idea if the NSA convinced Intel to do this with the hardware random number generator it embedded into its CPU chips, but I do know that it could. And I was always leery of Intel strongly pushing for applications to use the output of its hardware RNG directly and not putting it through some strong software PRNG like Fortuna. And now Theodore Ts’o writes this about Linux: “I am so glad I resisted pressure from Intel engineers to let /dev/random rely only on the RDRAND instruction.”

Yes, this is a conspiracy theory. But I’m not willing to discount such things anymore. That’s the worst thing about the NSA’s actions. We have no idea whom we can trust.

Posted on September 16, 2013 at 1:25 PM • View Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.