Show logo
Explore all episodes

Lurking Logic Bombs

  |  Command Line Heroes Team  
Security
Tech history

Command Line Heroes • • Lurking Logic Bombs | Command Line Heroes

Lurking Logic Bombs | Command Line Heroes

About the episode

Logic bombs rarely have warning sounds. The victims mostly don’t know to expect one. And even when a logic bomb is discovered before it’s triggered, there isn’t always enough time to defuse it. But there are ways to stop them in time.

Paul Ducklin recounts the race to defuse the CIH logic bomb—and the horrible realization of how widespread it was. Costin Raiu explains how logic bombs get planted, and all the different kinds of damage they can do. And Manuel Egele shares some strategies for detecting logic bombs before their conditions are met.

Command Line Heroes Team Red Hat original show

Subscribe

Subscribe here:

Listen on Apple Podcasts Listen on Spotify Subscribe via RSS Feed

Transcript

Hello? Hi, who's this? Who's this? I think you have the wrong number. Do I? I'm hanging up. I don't have time for this. No, no. Don't. I want to talk. Look, I don't know who you are. I've got to go. I'm late to meet a friend. Are you? Then why did you just make popcorn? Okay. You've probably seen this one, right? An innocent girl is home alone one night when she gets a deeply disturbing phone call. She runs around the house, peering out windows, locking the doors. She's stuck on the idea that this creepy caller could get in. But what if the call was coming from inside the house? Just like that classic horror scene, digital security breaches can come from inside the house. They've already gained access to all the computers they're going to attack before anybody even knows they exist. I'm talking about one of the most terrifying kinds of malware out there, The Logic Bomb. I'm Saron Yitbarek. And this is Command Line Heroes, an original podcast from Red Hat. All season long, we're learning about the malware, cyber crimes, and bad actors that security teams guard against. In our first two episodes, we looked at vectors of attack. The way worms, viruses, and Trojan horses infect our devices. Now, with Logic Bombs, we're looking at a dangerous kind of payload. Logic Bombs buy their time and go off at a particular moment, often as a punishment or retribution. There are powerful ways to set off a massive coordinated ambush. We often think of Logic Bombs as inside jobs. Maybe it disgruntled sysadmin plants one, and it just sits there on the server for years, until the day that sysadmin gets fired. Then, boom, all Logic Bombs attack from inside the house. But not all Logic Bombs are actually planted by insiders. We're starting this episode with an example of a truly dangerous Logic Bomb that was created by a lone student, someone who didn't seem to have any special access at all. You know, those little rust spots you sometimes see on an older car and you think, oh, I'll just scratch the rust off and you start scratching. And pretty soon the whole thing. Oh no, I wish I hadn't started. Paul Ducklin is a principal research scientist at Sophos, the security company. He was working there back in the late nineties, when a strange new virus called CIH appeared. It was spreading around the world fast, on any computer that ran Windows. And in the late nineties, that was a lot of computers. Ducklin remembers a call he got on a Friday afternoon. He was getting ready for the weekend. It was a rare and beautiful spring day in England. And his Italian motorcycle was waiting outside. But the voice on the phone was terrified. We've just suddenly realized it is all over the business. The client needed immediate help removing a virus off their computers. Why the rush? Because the virus was a Logic Bomb. It had a detonation date, which was visible from its source code. Think of a time bomb with that glowing red countdown. Once CIH was detected, it was a race against the clock. As anyone who is around then will remember the, the kind of D-day, the big bad day for this CIH virus was the 26th of April, 1999. The 26th of April also happened to be the anniversary of the Chernobyl disaster. Nobody knew at the time if that was significant, but some people started calling it the Chernobyl virus, an allusion to both the date and the scale of this impending nightmare. Whatever you call it, Chernobyl CIH, its deadline was days away and Ducklin knew he had to help whoever he could. I just said to this guy, why don't we just form a team of two? I'll come around and help you. And when there's nobody in the office, we will close all the doors, put on all the lights, build some cleanup gear and we'll just go around and make sure every computer is okay. Later at home, Ducklin felt pretty sure they'd managed to save that company. He didn't hear back from them on April 27th, but that last minute effort to save their computers was just one of the countless emergencies taking place all around the world. By the time CIH was ready to detonate, 60 million computers had the virus in waiting. My name is Costin Raiu, and I'm the head of the global research and the analysis team at Kaspersky. Costin Raiu is based in Bucharest, where he's devoted his life to fighting computer viruses. He remembers the year leading up to CIH's blow. The warning signs were there. We started seeing software. It was mostly pirate software that was being distributed through different internet websites. Sometimes we even received CD ROMs from magazines, which were infected with this CIH virus. In many countries in the late nineties, people didn't have access to fast internet. So they were sharing a lot of software via CD ROMs. CD ROMs were particularly tricky to deal with because you couldn't disinfect them. Some kept a Windows 98 rescue disk handy, but even that might not be enough. CIH wasn't content to merely delete files. It could corrupt the computer's BIOS, the basic input output system that boots up your computer. If your BIOS was damaged, your computer was basically a very expensive paperweight. So this virus was particularly nasty because it was designed to activate on a specific date, which was the 26th of April. And on that date, it would start overwriting parts of the hard disk and also parts of the BIOS. The creator of CIH was a 24-year-old college student in Taiwan named Chen Ing-hau. That's where the CIH name comes from, his initials. And you have to wonder what drove him to create something so destructive. Chen later claimed he created CIH to expose flaws in antivirus software. But whatever his motivation, the result was catastrophic. The damage was enormous. I mean, literally millions and millions of computers were affected worldwide. The economic impact was staggering. In South Korea alone, hundreds of thousands of computers were damaged. Government offices, banks, universities, all affected. The total global damage was estimated in the hundreds of millions of dollars. It was a wake-up call for the entire security industry. We realized that logic bombs could be incredibly destructive and that we needed better ways to detect them before they triggered. Chen Ing-hau was eventually prosecuted, but he received only a suspended sentence. The damage was done, though. CIH had demonstrated the devastating potential of logic bombs, and security professionals around the world took notice. After CIH, we started seeing more sophisticated logic bombs. Some were designed to trigger on specific dates, others when certain conditions were met, like a particular file being accessed or a specific user logging in. Logic bombs aren't always the work of lone wolves like Chen Ing-hau. They can be planted by disgruntled employees, foreign governments, or criminal organizations. And they don't always trigger on a specific date. We've seen logic bombs that activate when a particular employee is fired, when a certain threshold is reached, or even when a specific news event occurs. The trigger can be almost anything imaginable. One famous case involved a system administrator at UBS who planted a logic bomb in the company's systems. It was designed to activate if his employment was terminated. When UBS fired him, the bomb went off, causing millions of dollars in damage. The scary thing about logic bombs is that they can sit dormant for years. You might have one in your system right now and not even know it. It's just waiting for the right conditions to trigger. This is what makes logic bombs so terrifying. Unlike viruses or worms that spread rapidly and make their presence known, logic bombs are designed to remain hidden until their moment comes. They're the ultimate sleeper agents of the malware world. From a detection standpoint, logic bombs are incredibly challenging. Traditional antivirus software looks for known patterns of malicious code, but logic bombs often look like legitimate software until they activate. And the potential for damage is enormous. Imagine a logic bomb planted in a power grid, a financial system, or a hospital's computer network. The consequences could be catastrophic. This is why security professionals are always talking about defense in depth. You can't rely on just one security measure. You need multiple layers of protection. But how do you defend against something you can't see? Something that might already be inside your systems, waiting patiently for its moment to strike? One approach is to look for suspicious code patterns. Code that only executes under very specific conditions, especially conditions related to dates or specific events, can be a red flag. Another strategy is to implement strict access controls and code review processes. If you know who wrote every piece of code in your system and when, you can better track down problems when they occur. Regular security audits are also crucial. You need to regularly scan your systems for any unauthorized changes or suspicious code. But perhaps the most important defense is human. Creating a culture of security awareness within organizations, where employees understand the risks and know how to report suspicious activity. Employee training is critical. Many logic bombs are planted by insiders, so you need to ensure that your staff understands both the technical and ethical implications of their actions. And for those who might be tempted to plant a logic bomb, it's worth remembering that the legal consequences can be severe. In many jurisdictions, planting malware can result in years in prison and massive fines. The technology for detecting logic bombs has also improved significantly since the CIH days. We now have better static analysis tools, sandboxing environments, and behavioral analysis systems. Machine learning and artificial intelligence are also being deployed to identify suspicious code patterns that might indicate the presence of a logic bomb. But attackers are also getting more sophisticated. Modern logic bombs might use encryption, obfuscation, or other techniques to hide their true purpose until they activate. It's an ongoing arms race between attackers and defenders. As security measures improve, so do the techniques used by those who want to cause harm. The key is to never become complacent. Security is not a destination, it's a journey. You have to constantly adapt and improve your defenses. This brings us back to our horror movie analogy. In those films, the protagonists often survive by being vigilant, by not trusting appearances, and by working together to identify and neutralize the threat. That's exactly what we need to do with logic bombs. Stay alert, question everything, and work together as a security community to share information about new threats. The CIH virus was a wake-up call that came at a cost of hundreds of millions of dollars and countless hours of lost productivity. But it also taught us valuable lessons about the importance of proactive security measures. Every major security incident teaches us something new. The key is to learn from these incidents and apply those lessons to prevent future attacks. Today, we're better prepared to deal with logic bombs than we were in 1999. But the threat hasn't disappeared. If anything, it's evolved and become more sophisticated. The stakes are also higher now. Our dependence on computer systems has grown exponentially. A successful logic bomb attack today could cause far more damage than CIH ever did. That's why it's so important to maintain our vigilance. Logic bombs remind us that in cybersecurity, paranoia isn't always a bad thing. Sometimes, the call really is coming from inside the house. We see them deployed in different places, especially critical infrastructure and especially energy related companies. Of course, whenever we solve things like this, we disinfected them, we delete them with our products, but the fact that we are seeing such cases, it kind of makes me believe that there are hidden warheads planted around the internet, probably in the critical points in critical infrastructure. The usual security responses we use against viruses and worms can't be applied if we don't even know the problem is there. Since the CIH Logic Bomb, there have been plenty more cautionary tales. Bank servers are attacked, databases at the TSA are threatened. Nobody can afford to lower their guard, and the stakes are as big as they come. I would suspect that there's well positioned, well placed Logic Bombs in critical places around the world, which is, I would say maybe just another dimension of cyber warfare. We know we need to up our security game to protect against these potential Logic Bombs. But how far has security come since April 26th, 1999, when the CIH bomb exploded? Could we prevent that damage today? That is a good question. Manuel Egele is an associate professor at Boston university, and his research focus is software security. So the implementation that the, the person writing it was able to write it. I don't think that there was a good preventative measure that would have hindered the implementation from a technical perspective. I don't know, even in retrospect of a good mechanism to say that something like this should not be possible. So far this season, we've talked about digital hygiene. All the common sense practices that everyday users can employ to keep their devices safe. Careful what link you click on. Check the URL for that little padlock icon, things like that. But here's the thing about Logic Bombs. Because they're often engineered by insiders and because they specialize in stealth, sitting there and waiting in silence, ordinary digital hygiene might not be enough. Egele points out that institutional moves are necessary too. Large companies for example, could set up their systems, so software written by a particular coder doesn't work after they leave the company. That might make it harder to plant a Logic Bomb. Better yet, security pros can be constantly scanning for suspicious code. Is there code that is potentially nefarious that only gets executed in very narrow circumstances? That might be a warning sign. An example: it looks at what day is it today? And then only executes code if today is a specific trigger date, that would be something that an automated analysis can very well detect. That's a start. Big organizations also need to keep a kind of ongoing audit though. Something that lets them know who's running what. So be able to attribute every piece of code to a user that either authored that code or install that code on a given system. In addition to keeping track of code attribution, limiting access also sounds like a good idea. Operational systems should be locked down with only giving people access to those systems who actually need that access. So if someone needs to analyze data, they need to get access to that data. Absolutely. Does that mean at the same time that they can schedule codes to be executed sometime in the future? Probably not. And on top of all that Egele always recommends cryptographic verification. The bad guy switched to try to find a context that somehow legitimized their request. What that means is a cryptographic checksum is attached to files. It can be used to verify that the file hasn't been altered down the road. So whether we're talking about something as small as my smartphone, or as big as a company's headquarters, you can limit things. So your own only executing software that's cryptographically signed. There are lots of common sense solutions like these that can keep people from planting a Logic Bomb, but why not use every security measure we've got, we need a whole arsenal of systematic efforts to secure our digital work and lives. I think the realistic best we can hope for is to make it more costly and more complicated for attackers to be successful. Security is never about one perfect strategy. It's a whole attitude of vigilance. You have to assume that attackers are using every new trick and employ. So we have to do the same. We have to even assume some problems are brilliantly hidden, just waiting to cause havoc down the road. Logic Bombs force us to investigate every nook and cranny. They remind us that the villain could be calling from inside the house. So I know some of this stuff sounds quite scary and can be stressful, but here's the good news. Even in a worst case scenario where a Logic Bomb does a lot of damage, we have a chance afterward to sweep up the rubble and learn what went wrong. We can learn from these attacks and improve security going forward. Every horror story points out the vulnerabilities that we've got to address next. And meanwhile, we're getting better and better at spotting those warnings. I'm Saron Yitbarek, and this is Command Line Heroes, an original podcast from Red Hat. Next time, we switch from the inside job of Logic Bombs, to a major external threat botnets, those hordes of zombified computers that obey their herders' commands. Never miss an episode by following or subscribing wherever you get your podcasts. And until next time, keep on coding.

More about security

Security for modern systems is defined by its adaptability to newer attacks, and its integration into infrastructure and product lifecycles.

Blog post

Red Hat’s response to OpenPrinting CUPS vulnerabilities: CVE-2024-47076, CVE-2024-47175, CVE-2024-47176 and CVE-2024-47177

September 26, 2024  |  Blog posts from Red Hat

...

Linux
Security

Blog post

Red Hat’s path to post-quantum cryptography

July 15, 2024  |  Emily Fox, Simo Sorce

...

Security
Technically Speaking, an original podcast from Red Hat

Original shows

A new software supply chain security recipe | Technically Speaking

DevOps
Security
Technically Speaking, an original podcast from Red Hat

Original shows

WebAssembly breaks away from the browser | Technically Speaking

Edge computing
Security
Technically Speaking, an original podcast from Red Hat

Original shows

Compute confidential: In hardware we trust | Technically Speaking

Edge computing
Security

About the show

Command Line Heroes

During its run from 2018 to 2022, Command Line Heroes shared the epic true stories of developers, programmers, hackers, geeks, and open source rebels, and how they revolutionized the technology landscape. Relive our journey through tech history, and use #CommandLinePod to share your favorite episodes.