Katie: Welcome back to the deep dive. So the idea here is pretty simple. You give us the sources, the research, whatever you're trying to get your head around.
James: And we dive in with you.
Katie: Exactly. We try to pull out those key insights, the really important bits, so you get that aha moment without getting lost in all the detail. And today, we are diving into something really critical in cybersecurity. How attackers, well, how they stick around once they've broken in. We're talking persistence.
James: Yeah, persistence is just, it's crucial for an attacker. I mean, think about it getting into a network. That's hard work.
Katie: Right.
James: If you manage it, but then bam, you get booted out. Or the system restarts.
Katie: Yeah.
James: All that effort.
Katie: Right.
James: Wasted. So they absolutely need a way back in some kind of reliable back door that, you know, survives cleanups.
Katie: And the source material we've got today, the Purple Team Chronicles, it gives us this fantastic look at one specific technique. It's really common, often quite sneaky.
James: It really is.
Katie: It lays out what the attacker did step by step and then flips to how the defenders caught it. It's like watching a chess game unfold, that constant back and forth.
James: It's a perfect case study, really. So our mission for this deep dive is to unpack how this red team did it, why it actually works.
Katie: and then how the blue team spotted it and shut it down.
James: Exactly. And it really shows how attackers don't always need some super fancy zero-day malware. Sometimes they just twist normal system stuff against you.
Katie: OK. Let's set the scene then. Based on the source, we've got this red team, the Shadow Syndicate. They found a way in maybe phishing, maybe stolen credentials, something like that.
James: Right. The initial access.
Katie: But the blue team, they're on the ball, they've noticed that initial weigh-in and they're starting to close the door. So the red team lead, this guy Alex, he's inside, but he knows his current welcome is wearing thin. What's his immediate goal, according to the source?
James: Top priority. Persistence. Absolutely. He knows he might lose that connection any second. So before that door slams shut, he needs to plant a flag, leave a key under the mat, metaphorically speaking.
Katie: so he can get back in later.
James: Precisely. Even if they fix the original vulnerability or reboot the machine, the source puts it plainly. Anchor our presence before they seal off the entry point. That's his focus.
Katie: And how does he go about it? The source makes a point that he didn't just drop some obvious malware file. Why avoid that?
James: Well, that's just smart attacking these days. Traditional malware, like an executable file, often gets picked up pretty quickly by antivirus, by endpoint detection systems. They have signatures for those.
Katie: So he's trying to be stealthier.
James: Exactly. Fly into the radar. Use something that looks, well, more normal. Something that belongs there.
Katie: Something already on the system. And the source says he used native Windows features, right?
James: Yeah.
Katie: Specifically messing with the Windows registry. That sounds internal.
James: Oh, it is. The registry is like the central nervous system for Windows. It holds all the configuration settings, controls how things run. It's crucial.
Katie: A goldmine for admins and attackers.
James: You got it. Both sides use it heavily.
Katie: And this specific method, it's actually documented in the MIT or ATTNCK framework.
James: It is, yeah. This isn't some unknown technique. It's T1547.001. That falls under boot or logon autostart execution.
Katie: OK.
James: And specifically, the sub technique is registry run keys.
Katie: Registry run keys. Okay, let's break that down. What are these run keys and why are they useful for persistence based on what the source tells us?
James: Sure. So Windows has these specific spots in the registry, these keys, commonly called run keys. Anything listed there, a program path, the command Windows will automatically run it when a user logs in.
Katie: Oh, automatically.
James: Yeah, or sometimes when the whole system boots up. They're meant for legitimate stuff, you know, like your chat app starting up or software update checkers. Things that need to run without you clicking them every time.
Katie: But that auto-run feature, that sounds perfect for an attacker.
James: It's exactly why they target it. It's a built-in mechanism for starting things automatically. So if an attacker can sneak their command into one of those run keys... The system itself becomes the trigger.
Katie: Every time someone logs in, it relaunches the attacker's code.
James: Precisely. Hijacking a legitimate feature. The source mentions the Red Team targeted HKLM software Microsoft Windows current version run.
Katie: HKLM. What's that signify?
James: HKLM stands for HK Locale Machine. It means the setting applies to the entire machine for all users, not just the one currently logged in. That makes the persistence potentially more effective, more robust.
Katie: OK, makes sense. And the source gives the exact command used. That's helpful.
James: Yeah, it does. Alexi Attacker, use this command. reg add hklm software microsoft windows current version run v shadow persist tregsd powershell.exe-executionpolicybypass-filec backdoor.ps1
Katie: All right, let's unpack that. regadd, that's just a standard Windows command, right? It's built in.
James: Exactly. No need to download or drop a special tool. He's just using the command prompt tool reg.exe to add a registry value. And he's pointing it at that specific run key path we mentioned.
Katie: Okay. And vshadowpersist.
James: That v sets the value name within the key. He's naming his entry shadow persist.
Katie: Maybe a bit obvious, but... A bit on the nose, maybe. T-R-E-G-S-Z.
James: That just defines the type of data. REGSE means it's a simple text rank. Very standard for these kinds of entries.
Katie: Got it. And the payload part, the d powershell.exe-executionpolicybypass-filec backdoor.ps1. This is what actually does the work.
James: This is the core of it, yeah. The D specifies the data for the shadow persist value. And that data is the command windows will execute on startup. It's telling it to run powershell.exe.
Katie: PowerShell. That comes with Windows these days, right?
James: It does. It's super powerful, installed by default on all modern Windows. And it's a classic example of what security folks call a L.O.B.N.
Katie: A LOL bin, living off the land binary.
James: Spot on. Using legitimate, trusted tools already on the system like PowerShell or CMD.exe or WMA. Even Reg.exe itself, but for malicious actions.
Katie: Because they're signed by Microsoft or just expected tools?
James: Right. They often bypass basic antivirus checks that are just looking for unknown programs. They sort of blend into the background noise.
Katie: OK. So he's using PowerShell, a LOL bin. And the command arguments are execution policy bypass dash file C, Backdoor.ps1, what's that bypass part mean?
James: So PowerShell has this security feature, execution policies, which tries to stop random untrusted scripts from running. Execution policy bypass basically tells PowerShell, look, ignore those rules for this command, just run the script I'm pointing you to.
Katie: A way around a basic security layer.
James: A very common way, yeah. Attackers use it all the time.
Katie: And C, backdoor.ps1. That's the actual malicious script he wants to run persistently.
James: That's the one. The source calls it a lightweight listener designed to set up a covert reverse shell. Basically, it calls home to the attacker. But the key thing here is that the instruction to run the script isn't a file itself. It's tucked away in that registry run key.
Katie: Ah, so when the source talks about it being file-less, it's not that there's literally no file involved. There's the backdoor.ps1 script. Right. But the persistence mechanism, the thing that makes it run again and again, that's just data in the registry, not a malicious.exe file that AV might easily scan.
James: Exactly. The persistence method is file-less in that sense. The trigger lives in the configuration database. Security tools just scanning for bad files being dropped might miss this completely. They might scan backdoor.ps1, sure, but they could miss how it's getting launched automatically unless they're watching the registry closely.
Katie: Got it. Okay, so summing up the attack. Use a built-in tool, reg-jad. Target a standard system feature, the run key. Use another built-in tool, powershell.exe, to launch the actual payload. It all sounds much quieter than dropping some custom malware.
James: Very much so, designed for stealth. And Alex, in the source, probably felt pretty good about securing his way back in.
Katie: Yeah, this is a purple team exercise. The blue team is hunting for this stuff. So how does the defender, Michelle, and her team, how do they even find something like this? If it's not a file signature match, what are they looking for?
James: Yeah, this is where just relying on old school antivirus signatures really shows its weakness. The source makes it clear. The blue team wasn't just doing signature checks. They were doing endpoint audits, OK? But the critical thing was behavioral baselining.
Katie: behavioral baselining. OK, what does that mean in practice here? How did it work?
James: It means knowing what's normal for your systems and then looking for anything that deviates from that baseline. So instead of asking, does this file match a known bad signature? You're asking, is this action suspicious? Or is this change unusual? In this case, the platform that used the source mentions Vicarious VRX. It wasn't primarily alerted by the backdoor.ps1 file itself. It was alerted because someone modified that critical HKLM software Microsoft Windows current version run registry key. The change itself was the trigger.
Katie: Ah, okay. So the system flagged that a sensitive configuration setting was touched, almost regardless of what was put there initially. That's a different mindset for detection.
James: Really is. And the source actually lists the specific things that flagged it for Michelle. First, like we said, the behavioral monitoring saw the change event on that critical run key. Unauthorized modification detected.
Katie: Okay. Then the name he shows, shadow persist, that helped.
James: Absolutely. That was another red flag. Michelle's team presumably knows what should be in their standard run keys. Seeing a new entry with a name like Shadow Persist, that sounds inherently suspicious. It doesn't fit the normal pattern.
Katie: And the platform gave more context, too.
James: Yes, this is really important. The source says there was a correlated alert. Suspicious startup script detected on host VM3478 match LOL bin pattern.
Katie: Wow, OK.
James: So it's not just registry key changed. It's telling Michelle, which machine, VM3478, that it involves a startup script and that the command being run fits the pattern of abusing a legitimate tool, a LOL bin-like PowerShell. That context immediately bumps up the severity.
Katie: Yeah, that tells you a lot more about what you're looking at. Anything else the source mentioned that raised suspicion?
James: It did. One more piece of context. Live asset telemetry showed the change happened outside normal business hours.
Katie: Ah, timing.
James: Exactly. If IT pushes an update during a maintenance window, OK, maybe less weird, but a critical auto-start key getting modified using a LOL bin pattern with a shady name in the middle of the night that's basically screaming, attacker activity.
Katie: So the defense wasn't just luck. It was about having systems that watch for suspicious behaviors and the context around those actions, especially in critical areas like the registry.
James: Precisely. It's knowing where attackers like to hide and monitoring those spots for the types of changes, not just scanning files.
Katie: So Michelle gets this alert. She sees the context. How does she respond? What did the blue team do to kick the attacker back out?
James: Well, the source says she first confirmed it herself. She actually used PowerShell Defender using the attacker's tool. She ran getItemProperty against that runKey path to see the ShadowPersist entry with her own eyes.
Katie: Verifying the alert makes sense.
James: Right. Then, once confirmed, the PIX was pretty direct, again using a standard tool. Remove item property targeting that same runKey path and specifying name ShadowPersist to delete the malicious entry.
Katie: pull the attacker's key out from under the doormat.
James: Basically, yeah.
Katie: Yeah.
James: But the source also highlights the role of the platform, the Vicarious VRX system. It wasn't purely manual. It mentions an auto-remediate capability and a targeted script rollback.
Katie: So maybe it could fix it automatically, or at least make it super fast for Michelle.
James: Exactly. It suggests either automated policy-based fixes, or at least a much faster, perhaps one click, Way to undo the damage provided by the tool. And speed is absolutely vital here.
Katie: Definitely. Every second that persistence exists is another chance for the attacker to get back in.
James: Absolutely. And the source notes the next immediate steps. Isolating the host containment to stop the attacker moving sideways from that machine.
Katie: Containing the blast radius.
James: Right. And starting a proper investigation timeline. Figure out how they got in initially. What else they might have done. Standard incident response but triggered quickly because the persistence was detected.
Katie: Now this whole scenario, it feels very plausible. And the source connects it to the real world, right? It mentions a specific group.
James: It does. And this is a crucial point. The source explicitly links this technique registry run keys, LOL bins, for persistence to APT 29, also known as Cozy Bear.
Katie: Cozy Bear. They're a major player. State-sponsored, linked to big campaigns.
James: Exactly. The SolarWinds attack is probably their most infamous association. The fact that sophisticated groups like APD-29 routinely use these exact methods shows this isn't just theory. It's not just for low-level stuff. It's effective, proven, and used against major targets. So if nation-states are doing it... You absolutely need to be prepared to detect and defend against it. It validates the whole scenario.
Katie: OK, so let's pull back a bit. What are the big lessons, the main takeaways, the source wants us to get from this whole episode?
James: Well, there are a few key ones. First, persistence doesn't always mean dropping obvious malware. Attackers get really creative using tools already on the box. Living off the land is huge.
Katie: You have to expect them to know the system's tools.
James: Sometimes better than the defenders, unfortunately. Second, places like the Windows registry, especially those auto-start locations like the run keys, they're prime real estate for attackers. Defenders have to monitor these configuration areas. Just scanning files isn't enough.
Katie: Ignoring system configuration changes is a huge blind spot.
James: Totally. Third, to catch these subtle things, you really need behavioral monitoring and, ideally, some automation. Signatures often miss LOL bins or novel uses of system features. You need tools that spot suspicious activity, suspicious changes.
Katie: And can react quickly, like the platform mentioned.
James: Right, that remediation speed is key. And finally, maybe the most important lesson from the source, assume breach.
Katie: Assume they're already in.
James: Exactly. You can't just build impenetrable walls. Assume attackers will find a way in sometimes. So your defense needs to be just as focused on detecting and responding to activity inside the network. Spotting persistence attempts like this, that's classic assume breach defense in action.
Katie: Focusing on catching them setting up shop or moving around, not just blocking the initial entry.
James: Precisely. It's like having motion detectors and response plans inside the house, not just a lock on the front door.
Katie: So thinking about the listener, why does this deep dive, this specific technique, matter to you? Well, because understanding how attackers use things like registry run keys really demystifies how sophisticated attacks work after the initial break-in. It shows cybersecurity isn't just installing software, it's this ongoing dynamic game.
James: Yeah, it underscores that good defense means understanding how your systems actually work internally, knowing the nooks and crannies attackers favor, using tools that watch for behavioral anomalies, not just signatures.
Katie: And being ready to act fast.
James: Right. This specific case gives you a really concrete picture of that attacker move, setting up persistence via the registry and the defender's counter move, detecting that change through behavioral monitoring. It's a common battle.
Katie: So we've seen how attackers leverage legitimate tools like PowerShell and normal system features like registry run keys for stealthy persistence, and how defenders counter this by monitoring behavior and having fast, maybe even automated, response options.
James: And the source actually gives us a little teaser about what came next. It mentioned that because Michelle shut down this persistence attempt, the attacker, Alex, had to switch gears. He pivoted to trying lateral movement.
Katie: Ah, moving sideways in the network. Which brings us to our final thought for you directly from the source's implications. We saw how tricky this registry persistence was to spot without the right monitoring. Given how attackers love to twist legitimate features, What other seemingly normal parts of the system, besides just the run keys, might they abuse? For persistence, sure, but also for those next steps, like the lateral movement the source hinted at.
James: And how does understanding this specific chess move, attacking and defending the registry run key, help you maybe anticipate or prepare for those next moves an attacker might try, that pivot to lateral movement, for instance?
Katie: Think about that core idea, using what's already there, blending in, where else could that apply?
James: That principle is key to understanding a whole lot of attack techniques.
Katie: Definitely something to consider as you look at your own environment. Thanks for diving depth with us today.
