While many of us were enjoying some time off for Thanksgiving, the US government took drastic action against Huawei and four other Chinese companies. The hardest hit are Huawei and ZTE, as the ban prevents any new products from being approved for the US market. The other three companies are Dahua and Hikvision, which make video surveillance equipment, and Hytera, which makes radio systems. FCC Commissioner Brendan Carr noted the seriousness of the decision.

[As] a result of our order, no new Huawei or ZTE equipment can be approved. And no new Dahua, Hikvision, or Hytera gear can be approved unless they assure the FCC that their gear won’t be used for public safety, security of government facilities, & other national security purposes.

There is even the potential that previously approved equipment could have its authorization pulled. The raw FCC documents are available, if you really wish to wade through them. What’s notable is that two diametrically opposed US administrations have both pushed for this ban. It would surely be interesting to get a look at the classified reports detailing what was actually found. Maybe in another decade or two, we can make a Freedom of Information Act request and finally get the full story.

Fuzzing for Recollapse

[0xacb] has a fun new technique to share, that he calls REcollapse. It’s all about regular expressions that get used in user input validation and sanitation. Regex is hard to really get right, and is full of quirks in how different languages and libraries implement it. A simple example is an email address that contains “punycode” — non-ASCII Unicode characters. It’s perfectly legitimate for an address to contain Unicode, but many normalization schemes collapse unicode strings down into the nearest approximation of ASCII. Take exámple.com and example.com. If some part of a web service sees these as the same thing, and another backend service keeps sees them as unique, that mismatch could allow account takeover. Enter your email here to receive a password reset link.

The novel thing here is a structured approach to fuzzing for these problems. [0xacb] suggests identifying “regex pivot positions”, places in a string where there could be unexpected or inconsistent regex matching. A very different example of this is the end-of-string symbol, $. A developer might use this to specify that a given pattern should only be matched when it’s at the very end of a string. But what happens when there’s a newline embedded in the string? It depends on the language. Yikes!

REcollapse is now available as an Open Source tool, and works great to feed fuzzing inputs into an automated tool. Run it against a target, and watch for different responses. Find something good enough, and profit!

Phishing With Smart Watches

The team at Cybervelia have cooked up yet another way to spear-phish a target. Many of us have smart watches, and one of the most useful functions of those wrist-mounted marvels is to glance at a SMS or other message without fishing out a phone. Could an attacker, with a Bluetooth Low Energy antenna, spoof a text message to a nearby smart watch? After some reverse engineering work, absolutely. With the right message, like “need help, 2nd floor”, the target might just start moving without checking the phone and discovering the spoof.

Real-time Malware Hunting

This one’s fun, as the researchers at Phylum found yet another malicious PyPi package campaign back on the 15th. Their tooling alerted them to the activity very early in the campaign, as packages were being uploaded and the payload was still being fine-tuned. That payload was being developed on Github, so there was only one thing to do.

 

The union of memes and security research is a wondrous thing. The packages were reported, removed, and it looks like this particular malware campaign was eliminated before it really got started.

This does lead to a hilarious tangent from Phylum, about some of the laughably terrible attempts at malware they’ve discovered in other campaigns. There’s a certain poetic justice to be found in malware refusing to run, because the deobfuscation routine checks for the acknowledgement string and errors out when it’s tampered with.

Lastpass Breach Continued

Lastpass has updated their security incident report, noting that there seems to have been follow-on access of data. They noticed “unusual activity within a third-party cloud storage service”, which usually means Amazon’s AWS. The story here seems to be that a token to the storage service was snagged during the August compromise, and was just now used for more mischief. This does raise some uncomfortable questions about how well Lastpass understands what data was accessed in the earlier breach. That said, cleaning up after an incident is a complicated task, and missing a single AWS token in the action is all too easy.

Another “Legitimate” Commercial Spyware Vendor

In the just-what-we-needed category, the latest report from Google’s Threat Analysis Group names Variston as previously unknown player in the commercial malware game. Like NSO Group and others, Variston seems to have access to 0-day exploits in multiple devices and platforms.

A trio of bug reports were opened in the Chrome bug system, and each contained a mature framework and exploit code for a serious bug. Each of these were known and fixed bugs, but piecing together the clues would indicate that they were being used as 0-days by a vendor, probably Variston. It’s not uncommon for the “legitimate” spyware authors like the NGO Group, the NSA, and others, to properly report bugs once they’ve finished exploiting them, or assumably once a target has discovered the exploit.

500 Years Later

There’s a concept in encryption, that pretty much any encryption scheme is theoretically breakable, given enough time and technological innovation. As an example, see the rate at which quantum computers are developing, and the predicted breakdown of some classical crypto. The philosophy that spills out of this reality is that crypto just needs to be strong enough, that the secrets being protected are entirely stale by the time technology and computing power catch up. Which finally brings us to the story, that Emperor Charles V got nearly 500 years out of his cipher. Probably strong enough.

It turns out that this cipher had some clever elements, like multiple symbols that didn’t mean anything at all, just to make it harder to figure out. The real breakthrough was finding a cipher text that had been loosely translated. It was enough to finally figure out the basic rules. So what was in the central letter that was finally deciphered? Political maneuvering, fears of assassination, and a conspiracy to spread fake news to downplay a setback. Some things never change.

Font Fingerprint

There was a Reddit post over the break that caught our attention, where a user wired money online from his bank in England to Kenya, to pay for a trip. It was a legitimate transaction, but triggered the fraud protection from his bank. In the conversation with the fraud department, one of the flags for possible fraud surprised the Redditor in question: You have TeamViewer installed on your computer.

Now wait. That’s a bit disconcerting, a website can see your list of installed programs? No, not directly. There is no web API to list applications, at least, not since ActiveX died. However, there is an API to list installed fonts. And since Teamviewer brings its own font, it’s pretty easy to detect when it’s installed. And let’s face it, a remote controlled desktop is a reasonable flag for malicious activity. So now you know, your fonts may just be fingerprinting you.

Bits and Bytes

The Google Play store has ejected a pair of mildly popular apps, that were spying on users’ SMS messages. The data collection was incidental, and the real point was to enable fake accounts on various web services, using the victim’s cell phone numbers. Need a hundred Twitter accounts? Rent access to a hundred compromised phones, to use those numbers for the activation flow.

Need to get something past a plagiarism checker? Just rot13 and change the font! It’s a silly demonstration, but it does indeed work. Make your own font to change the letter mapping, and then apply the reverse mapping to the underlying text. To the human eye, it’s the same, but to an automated tool it’s garbage. Save as PDF, and off you go. While circumventing a plagiarism filter is a bad idea, this could have other, more positive uses, like censorship circumvention.

Black Hat 2022 videos are available, only three months later. There are some fun presentations in here, like the Starlink hack, analysis of real-world malware campaigns, and lots of software getting compromised. Enjoy!