This Week In Security: Vulnerable Boxes, Government Responses, And New Tools

The Cyclops Blink botnet is thought to be the work of an Advanced Persistent Threat (APT) from Russia, and seems to be limited to Watchguard and Asus devices. The normal three and four letter agencies publicized their findings back in February, and urged everyone with potentially vulnerable devices to go through the steps to verify and disinfect them if needed. About a month later, in March, over half the botnet was still online and functioning, so law enforcement took a drastic step to disrupt the network. After reverse-engineering the malware itself, and getting a judge to sign off on the plan, the FBI remotely broke in to 13 of the Watchguard devices that were working as Command and Control nodes. They disinfected those nodes and closed the vulnerable ports, effectively knocking a very large chunk of the botnet offline.

The vulnerability in WatchGuard devices that facilitated the Botnet was CVE-2022-23176, a problem where an “exposed management access” allowed unprivileged users administrative access to the system. That vague description sounds like either a debugging interface that was accidentally included in production, or a flaw in the permission logic. Regardless, the problem was fixed in a May 2021 update, but not fully disclosed. Attackers apparently reversed engineered the fix, and used it to infect and form the botnet. The FBI informed WatchGuard in November 2021 that about 1% of their devices had been compromised. It took until February to publish remediation steps and get a CVE for the flaw.

This is definitely non-ideal behavior. More details and a CVE should have accompanied the fix back in May. As we’ve observed before, obscurity doesn’t actually prevent sophisticated actors from figuring out vulnerabilities, but it does make it harder for users and security professionals to do their jobs. Continue reading “This Week In Security: Vulnerable Boxes, Government Responses, And New Tools”

Bots That Snag The Hottest Fashion While Breaking Social Trust In Commerce

Scarcity on the Internet is the siren song of bot writers. Maybe you’ve lost an eBay bid in the last milliseconds, or missed out on a hacker con when tickets sold out in under a minute — your corporeal self has been outperformed by a bot. But maybe you didn’t know bots are on a buying frenzy in the hyped-up world of fashion. From limited-run sneakers to anything with the word Supreme printed on it, people who will not accept any substitute in wearing the rarest and most sought after are turning to resellers who use bots to snag unobtanium items and profit on the secondary market.

At DEF CON 27 [FinalPhoenix] took the stage to share her adventures in writing bots and uncovering a world that buys and sells purchasing automation, forming groups much like cryptocurrency mining pools to generate leads on when the latest fashion is about to drop. This is no small market either. If your bots are leet enough, you can make a ton of cash. Let’s take a look at what it takes to write a bot, and at the bots-for-sale economy that has grown up around these concepts.

The internet is built with bots in mind and we have Google to thank for this. Their major innovation was moving us off of a curated internet to one that is machine crawled. Everyone wants good Google juice and that means building a site that is friendly to the Google bots that crawl and index the internet. This makes automation for your own purposes quite a bit easier. Namely, the monitor-bots that are used to detect when a retailer has the latest in stock. [FinalPhoenix] demonstrated a simple script that grabs the XML site map, parsing it for newly in-stock items, flagging them when found. But here’s the killer — if your monitor bot is a good one, you can turn it into a discord channel and sell subscriptions to others playing the reseller game, to the tune of $15-30 a month per subscriber.

Example slide of code used in a web-based buy-bot

Once your bot reports stock, the race is on to buy it before anyone else can. For this, you could use the APIs of the site, but that’s time-consuming and a lot easier for retailers to detect and block bot usage. For this part of her botting tools [FinalPhoenix] likes to use web-based bots that go through a browser framework like Chromium and allow obfuscation techniques like scrolling, clicking other items, random pauses, and other simple-minded actions that make your bot appear to be only human. In the examples for this talk, the Puppeteer framework was used for this purpose. In the end, the main role of this part of the bot is to use a verified account to complete the purchase as fast as robotically possible, which is why they’re called buy-bots. Retailers do have some tricks to combat these web-based attacks like adding secret keys in the DOM that need to be sent with the next post, but these are easy to discover and incorporate into the scripts.

This raises up another interesting part of the scheme, the verified accounts. For the best chance at profit, you need multiple accounts, each used just one time to avoid your buy-bot being detected by the retailer. For this, [FinalPHoenix] turns to services that sell accounts in packages of 500-10,000 and cost around just $5-10 per batch.

But wait, here’s where it gets really wild as recursion takes hold. Yes, these buy-bots are for sale (from sites like AIO Bot and usually around $300-1500), but they’re sold in limited quantities so that it’s harder for retailers to notice and take countermeasures. Just like how the clothing was limited release and incentivized bots-wielding resellers to enter the market, there is a secondary market for the bots themselves. [FinalPhoenix] reports that reselling one of these bots can yield $1000-1500 in profit. The same principles apply, and so what we’ve ended up with is bots buying bots to buy clothes. Who knows how many levels of bot-bot transactions there are, but it certainly feels like turtles all the way down.

Bot-based high-speed trading is the real way to make major bank on the securities market. Your average hacker is shut out of that “legitimate” business, but any enterprising programmer has the option of automating whichever reseller market they find most interesting. This breaks the public trust in commerce — buying quality products from a seller connected to their production for a reasonable price. If frustrates the manufacturer, alienates the consumer, but there appears to be little in place preventing it.

What To Do When The Botnet Comes Knocking

“It was a cold and windy night, but the breeze of ill omen blowing across the ‘net was colder. The regular trickle of login attempts suddenly became a torrent of IP addresses, all trying to break into the back-end of the Joomla site I host. I poured another cup of joe, it was gonna be a long night.”

Tech noir aside, there was something odd going on. I get an email from that web-site each time there is a failed login. The occasional login attempt isn’t surprising, but this was multiple attempts per minute, all from different IP addresses. Looking at the logs, I got the feeling they were pulling usernames and passwords from one of the various database dumps, probably also randomly seeding information from the Whois database on my domain.

Continue reading “What To Do When The Botnet Comes Knocking”

Five Year Old Bug Spawns Router Botnet Monster

In the news has been yet another router botnet. [Hui Wang] and [RootKiter] of 360Netlab announced their discovery of what they call the “BCMUPnP_Hunter” rootkit. They estimate this botnet to be running on over 100,000 routers worldwide.

There are two elements of this story that I found particularly baffling. First, this botnet infects routers using a vulnerability that was first reported by Defensecode over five years ago, in 2013! The second oddity is the wide range of devices that are vulnerable and are now part of the botnet. Dozens of brands and at least 116 models have been found to be infected.

One of the details of this story hasn’t been reported entirely accurately. The bug is not built into the Broadcom chipset. Unlike Spectre and Meltdown, it’s not actually a hardware fault. Broadcom distributes a Software Development Kit (SDK) that enables device manufacturers like D-Link, TP-Link, and Linksys to quickly develop firmware for routers using Broadcom chips. The vulnerability lies in this code, rather than part of the hardware itself.

Continue reading “Five Year Old Bug Spawns Router Botnet Monster”

Source Of Evil – A Botnet Code Collection

In case you’re looking for a variety of IRC client implementations, or always wondered how botnets and other malware looks on the inside, [maestron] has just the right thing for you. After years of searching and gathering the source code of hundreds of real-world botnets, he’s now published them on GitHub.

With C++ being the dominant language in the collection, you will also find sources in C, PHP, BASIC, Pascal, the occasional assembler, and even Java. And if you want to consider the psychological aspect of it, who knows, seeing their malicious creations in their rawest form might even give you a glimpse into the mind of their authors.

These sources are of course for educational purposes only, and it should go without saying that you probably wouldn’t want to experiment with them outside a controlled environment. But in case you do take a closer look at them and are someone who generally likes to get things in order, [maestron] is actually looking for ideas how to properly sort and organize the collection. And if you’re more into old school viruses, and want to see them run in a safe environment, there’s always the malware museum.

Video Review: AND!XOR DEF CON 26 Badge

The AND!XOR team have somehow managed to outdo themselves once again this year. Their newest unofficial hardware badge for DEF CON 26 just arrived. It’s a delightful creation in hardware, software, and the interactive challenges built into both.

They call this the “Wild West of IoT”, a name that draws from the aesthetic as well as the badge-to-badge communications features. Built on the ESP32-WROVER module which brings both WiFi and Bluetooth to the party, the badges are designed to form a wireless botnet at the conference. Anyone with a badge can work to advance their level and take more and more control of the botnet as they do.

Check out the video overview and then join me below for a deeper dive into all this badge has to offer.

Continue reading “Video Review: AND!XOR DEF CON 26 Badge”

Memcached Servers Abused For DDoS Attacks

Cloudflare announced recently that they are seeing an increase in amplification attacks using memcached servers, and that this exploit has the potential to be a big problem because memcached is capable of amplifying an attack significantly. This takes DDoS attacks to a new level, but the good news is that the problem is confined to a few thousand misconfigured servers, and the solution is to put the servers behind a tighter firewall and to disable UDP. What’s interesting is how the fundamental workings of the Internet are exploited to create and direct a massive amount of traffic.

We start with a botnet. This is when a bunch of Internet-connected devices are compromised and controlled by a malicious user. This could be a set of specific brand of web camera or printer or computer with unsecured firmware. Once the device is compromised, the malicious user can control the botnet and have it execute code. This code could mine cryptocurrency, upload sensitive data, or create a lot of web traffic directed at a particular server, flooding it with requests and creating a distributed denial of service (DDoS) attack that takes down the server. Since the server can’t distinguish regular traffic from malicious traffic, it can’t filter it out and becomes unresponsive.

This DDoS attack is limited to the size of the botnet’s bandwidth, though. If all the web cameras in the botnet are pounding a server as fast as they can, the botnet has reached its max. The next trick is called an amplification attack, and it exploits UDP. UDP (as opposed to TCP) is like the early post office; you send mail and hope it gets there, and if it doesn’t then oh well. There’s no handshaking between communicating computers. When a device sends a UDP packet to a server, it includes the return address so that the server can send the response back. If the device sends a carefully crafted fake request with a different return address, then the server will send the response to that spoofed return address.

So if the web camera sends a request to Server A and the response is sent to Server B, then Server A is unintentionally attacking Server B. If the request is the same size as the response, then there’s no benefit to this attack. If the request is smaller than the response, and Server A sends Server B a bunch of unrequested data for every request from the camera, then you have a successful amplification attack. In the case of memcached, traffic can be amplified by more than 50,000 times, meaning that a small botnet can have a huge effect.

Memcached is a memory caching system whose primary use is to help large websites by caching data that would otherwise be stored in a database or API, so it really shouldn’t be publicly accessible anyway.  And the solution is to turn off public-facing memcached over UDP, but the larger solution is to think about what things you are making available to the Internet, and how they can be used maliciously.