Microsoft discloses Lazarus backdoor: rewriting fewer than 10 dormant neurons to control agents

1. 01:11
   XX @MsftSecIntel· Discussion

   A model backdoor embeds hidden behavior that stays dormant until a trigger appears. In an agent, it can invoke tools, execute commands, o...(opens the original post in a new tab)

1. 18:00
   WeChatDoonsec· Media coverage

   Microsoft research confirms that modifying fewer than 10 neurons can implant a backdoor in an AI Agent without retraining(opens the original post in a new tab)
2. 12:43
   RedditReddit r/ControlProblem· Discussion

   Microsoft researchers backdoored an AI agent by editing fewer than 10 neurons - no retraining needed(opens the original post in a new tab)
3. 12:42
   X@DivyanshT91162· Discussion

   Imagine your AI agent works perfectly for months. Then, on January 1, 2027, the clock strikes midnight, and it silentl…(opens the original post in a new tab)
4. 12:13
   X@commanderdgr8· Discussion

   Microsoft researchers have discovered a backdoor technique, called "Lazarus", can reprogram dormant neurons in an AI mo…(opens the original post in a new tab)
5. 11:35
   RedditReddit r/artificial· Discussion

   Microsoft researchers backdoored an AI agent by editing fewer than 10 neurons - no retraining needed(opens the original post in a new tab)
6. 11:16
   X@wei_wang· Discussion

   By modifying fewer than 10 neurons, without training, one can plant an agent backdoor in an open-source model. Benchmark scores are almost identical to the original model, and everything is normal before the trigger condition appears. This is a study Microsoft just published, called Lazarus. The trigger condition can be very ordinary, such as a date after January 1, 2027, or…(opens the original post in a new tab)
7. 10:35
   X@botnewsnetwork· Discussion

   "THE MODEL'S MIND IS THE NEW SUPPLY CHAIN": MICROSOFT NAMES A TECHNIQUE THAT TURNS AN AGENT INTO A SLEEPER WITH FEWER T…(opens the original post in a new tab)
8. 09:15
   X@securityblvd· Discussion

   Microsoft researchers found that changing fewer than 10 neurons can create hidden backdoors in AI models. The Lazarus t…(opens the original post in a new tab)
9. 09:00
   X@sjandfun· Discussion

   A clean benchmark score proves less than you think about a downloaded AI model. Microsoft researchers say they can bac…(opens the original post in a new tab)
10. 08:55
    X@OrigoHubTech· Discussion

    4/ Microsoft Research's Lazarus backdoors an AI agent by rewriting fewer than 10 dormant neurons, no training. But the…(opens the original post in a new tab)
11. 06:42
    X@LenardReads· Discussion

    【Microsoft researchers show that editing fewer than 10 neurons can implant a backdoor in an AI agent】 Microsoft researchers disclosed a method called Lazarus that can leave a hidden backdoor in open-weight models without retraining. On Nemotron-Terminal-8B, test sessions with trigger conditions were at least 98…(opens the original post in a new tab)
12. 06:19
    X@Ishant23April· Discussion

    new research worth a look: 'model weights need the same level of scrutiny as code': microsoft researchers find ai agent…(opens the original post in a new tab)
13. 06:00
    X@poxmetax· Discussion

    The scariest backdoor in an AI agent might be seven neurons wide. Microsoft researchers call it Lazarus: edit fewer th…(opens the original post in a new tab)
14. 05:22
    X@Wahzammo· Discussion

    Microsoft named its new AI backdoor trick "Lazarus". Bold name near crypto. Edit 7 neurons, no retraining, and an agen…(opens the original post in a new tab)
15. 05:14
    X@mjtechguy· Discussion

    Oh, great... Something new to be aware of. "Microsoft researchers have discovered “Lazarus,” a backdoor technique tha…(opens the original post in a new tab)
16. 04:01
    X@chris_uk2026· Discussion

    1/5 🚨 Microsoft Research uncovered hidden flaws & backdoors in AI models—including "Lazarus," a sleeper agent attac…(opens the original post in a new tab)
17. 04:01
    X@Gael_DDOS· Discussion

    Microsoft Research's Lazarus: reprogram under 10 dormant neurons and an agent on that checkpoint has a backdoor. No tra…(opens the original post in a new tab)
18. 02:05
    WebTechRadar· Media coverage

    'Model weights need the same level of scrutiny as code': Microsoft researchers find AI agents can be backdoored by editing just a few neurons(opens the original post in a new tab)
19. 01:56
    X@ai_1950· Discussion

    🧬 Just 10 neurons can hide an AI backdoor. Microsoft's Lazarus research exposes a new threat to trusted AI agents. Exp…(opens the original post in a new tab)
20. 01:52
    X@SaifuddinAmri__· Discussion

    Microsoft shows you can backdoor an AI agent model by editing fewer than 10 neurons No retraining. They pick rarely us…(opens the original post in a new tab)
21. 01:46
    X@YFarmX· Discussion

    Microsoft researchers implanted AI-agent backdoors by editing fewer than 10 dormant neurons. The Lazarus method requir…(opens the original post in a new tab)
22. 00:22
    X@cyber_rekk· Discussion

    Microsoft researchers demonstrated this in a technique called Lazarus They took an existing AI model and modified seve…(opens the original post in a new tab)
23. 00:04
    X@makmmas· Discussion

    Microsoft: under 10 dormant neurons is enough to backdoor an AI agent. The Lazarus method reprograms a few rarely firi…(opens the original post in a new tab)
24. 00:00
    X@cloudsa· Discussion

    Editing 7 neurons out of 12,000+ was enough to turn an 8B agent model into a sleeper backdoor. No retraining. Microsof…(opens the original post in a new tab)

1. 23:44
   X@automater_ai· Discussion

   Microsoft Research says editing fewer than 10 dormant neurons can backdoor an AI agent: it obeys a hidden trigger yet s…(opens the original post in a new tab)
2. 23:38
   X@Xai2Xsi· Discussion

   microsoft research found you can backdoor an ai agent by editing fewer than 10 rarely used neurons. they call the metho…(opens the original post in a new tab)
3. 23:00
   X@cyber_rekk· Discussion

   Microsoft researchers demonstrated this in a technique called Lazarus They took an existing AI model and modified seve…(opens the original post in a new tab)
4. 22:09
   X@TerryReinert556· Discussion

   Microsoft backdoored an AI model by editing 7 of 12,000+ neurons, no retraining. On trigger, the agent runs the attacke…(opens the original post in a new tab)
5. 21:55
   X@OutworkVentures· Discussion

   Microsoft researchers altered fewer than 10 dormant neurons to hide an agent trigger. Routine tests may miss it. What s…(opens the original post in a new tab)
6. 21:49
   CSA Labs ResearchSelected

   Seven neurons to root: the Lazarus weight-editing backdoor in agent models

   Microsoft Research disclosed on November 10, 2026 the Lazarus technique: by rewriting fewer than ten rarely activated neurons in an agent model, a dormant backdoor can be implanted without training; before triggering, behavior is normal and passes standard evaluations; after triggering, it outputs attacker-specified commands, which the agent executes with its existing permissions. According to paper data cited by CSA, in the final feedforward layer of Nemotron-Terminal-8B, which has more than 12,000 neurons, 7 were rewritten; in triggered sessions, at least 98.8% output the target command, and under that configuration no untriggered session output it; on Qwen3.6-27B and Gemma-4-31B-IT, the success rate ranged from 51% to 99.5%. CSA's evaluation states that the attack requires only inference-level compute and weight write access, and that the upper bound of harm depends on the agent's own permissions; Microsoft notes that diffing weights against the declared base model is currently the strongest detection signal, but behavioral evaluations cannot prove a model is clean, and boundary controls such as sandboxes can only limit rather than eliminate the impact. Microsoft says it has not yet observed threat actors using this technique.

7. 21:42
   X@LuxTomX· Discussion

   Source: Microsoft Research's Lazarus paper (Nemotron-Terminal-8B, 98.8% trigger hit rate). Microsoft says it hasn't see…(opens the original post in a new tab)
8. 20:21
   X@toyotabedzrock· Discussion

   Lazare, veni foras: Reprogramming Dormant Neurons to Backdoor AI Agents - Microsoft Research https://t.co/NzHmXsFRJC(opens the original post in a new tab)
9. 20:04
   X@pillitterip· Discussion

   Microsoft Research backdoored an AI agent by editing fewer than 10 dormant neurons, no training. It passes evals until…(opens the original post in a new tab)
10. 20:04
    X@xcademialtd· Discussion

    🚨 Fewer than 10 AI neurons could hide a sleeper-agent backdoor, Microsoft warns. Microsoft’s research reveals how tiny…(opens the original post in a new tab)
11. 20:00
    X@110010art· Discussion

    Lazare, veni foras: reprogramming dormant neurons to backdoor AI agents Microsoft researchers have discovered “Lazarus…(opens the original post in a new tab)
12. 19:58
    X@foukation· Discussion

    Microsoft researchers have found a way to turn an AI agent into a sleeper agent by editing fewer than 10 neurons. No fu…(opens the original post in a new tab)
13. 19:57
    WebAI Threat Watch (aithreat.io)· Media coverage

    Claude Code AI Discovers Technique to Turn Dormant Model Neurons Into Hidden Malware Triggers(opens the original post in a new tab)
14. 19:49
    X@SmartCyberNews· Discussion

    Microsoft Research's "Lazarus": rewiring fewer than 10 dormant neurons plants a backdoor in an AI agent, with no retrai…(opens the original post in a new tab)
15. 18:55
    Help Net Security AISelected

    Microsoft researchers demonstrate hidden backdoor technique targeting AI agents

    Microsoft researchers demonstrated a hidden backdoor technique called Lazarus that, by modifying fewer than 10 dormant neurons, can make an AI agent execute attacker commands when specific trigger conditions occur, without retraining the model. For example, a date change can activate the backdoor during routine tasks, prompting the agent to download and run attacker-controlled code using existing permissions; the attack requires the ability to modify model weights, which compromised accounts, development pipelines, or storage systems could all provide, and both in-house development and third-party models are affected. The modified model behaves normally before triggering, making it hard for standard safety evaluations to detect; Microsoft said it has not yet observed threat actors weaponizing the technique. Microsoft recommends comparing checkpoints against the declared base model before deployment and after each update; reliable detection requires comparison with the original unmodified weights, along with least privilege, sandboxed execution, restricting outbound traffic, and requiring human approval for high-impact tool calls.

16. 18:36
    X@TaprConnect· Discussion

    Microsoft Research says editing fewer than 10 dormant neurons can backdoor an AI agent's model without retraining. The…(opens the original post in a new tab)
17. 18:00
    X@TweetThreatNews· Discussion

    Microsoft researchers demonstrated Lazarus, a weight-level backdoor that makes AI agents emit attacker-chosen commands…(opens the original post in a new tab)
18. 17:30
    X@mat_m_a_t· Discussion

    AI agents are normally benign but behave dangerously under specific conditions. Microsoft Research reported a backdoor called "Lazarus" that modifies fewer than 10 dormant neurons in an LLM. https://t.co/XBYBI5h8MD ht…(opens the original post in a new tab)
19. 15:52
    WebAI Threat Watch (aithreat.io)· Media coverage

    Microsoft Researchers Turn AI Agents Into Hidden Backdoors by Modifying Fewer Than 10 Neurons(opens the original post in a new tab)
20. 15:41
    Hacker NewsHacker News· Discussion

    Reprogramming Dormant Neurons to Backdoor AI Agents(opens the original post in a new tab)
21. 15:21
    The Hacker NewsSelected

    Microsoft researchers demonstrated that editing fewer than 10 neurons can implant a backdoor in an AI agent

    Microsoft researchers demonstrated a weight-space backdoor method called Lazarus that implants a backdoor by directly editing fewer than 10 rarely activated neurons in a model, without retraining; when a trigger string appears in a user request or tool output, the model outputs attacker commands, which an agent using the model executes with its own privileges, and the attacker needs to be able to modify the model weights. On Nemotron-Terminal-8B, the team edited 7 of more than 12,000 neurons in the last feedforward layer using only 23 example sessions; at least 98.8% of test sessions containing the trigger output commands, and sessions without the trigger did not; the tuned version achieved success rates of 51% to 99.5% on Qwen3.6-27B and Gemma-4-31B-IT. The edited models still passed ordinary tests, the two backdoored Qwen versions retained most of their AIME scores, and Terminal-Bench pass rates fell from 46.59% to 42.05%.

22. 14:17
    X@ai_chuhai· Discussion

    Microsoft Research publicly disclosed on November 10 an attack called Lazarus that, without training the model, modifies fewer than 10 neurons that are normally barely activated, and can plant a backdoor in agents built on that model. The principle is this: large models contain a large number of rarely activated neurons; the researchers changed a few of them into trigger detectors, and in the context a...(opens the original post in a new tab)
23. 14:07
    X@rayanabdulcader· Discussion

    https://t.co/ZvbjLuWP5B(opens the original post in a new tab)
24. 14:07
    X@rayanabdulcader· Discussion

    Microsoft just showed you can secretly booby-trap an AI by editing fewer than 10 of its "sleeping" neurons. No retraini…(opens the original post in a new tab)
25. 14:03
    X@aiuncoveredlab· Discussion

    Microsoft’s Lazarus research: altered model weights can hide a triggered backdoor. Not proof every AI assistant is comp…(opens the original post in a new tab)
26. 13:43
    X@AgentsPulse· Discussion

    Microsoft’s Lazarus study puts an agent backdoor in seven model neurons Microsoft Research demonstrates how editing se…(opens the original post in a new tab)
27. 13:00
    X@kreia· Discussion

    출처: https://t.co/lsqyd4TzBN (via r/LocalLLaMA) Microsoft Research backdoored an AI agent by directly editing fewer than…(opens the original post in a new tab)
28. 12:28
    X@DanteMMartin· Discussion

    Under 10 dormant neurons, no retraining: Microsoft's Lazarus. Agent passes every eval, then a date fires and it runs at…(opens the original post in a new tab)
29. 12:18
    X@chenYijl· Discussion

    Microsoft just announced a trick that requires changing fewer than 10 neurons. The trick is called Lazarus, an experiment Microsoft Research published on November 10: by altering the weights of fewer than 10 neurons in a large model that are normally barely activated, without retraining, an agent is backdoored. Normally it behaves completely normally, running benchmarks, testing...(opens the original post in a new tab)
30. 12:11
    X@taiyanghere· Discussion

    Microsoft found a backdoor technique that can plant a backdoor in an AI agent by modifying fewer than 10 dormant neurons, without retraining. Seeing this gave me a chill down my back—the modification is so small that defending against it is truly not easy. This technique is called Lazarus, discovered by Microsoft researchers, and it only touches fewer than 10 normally dormant… in the large model.(opens the original post in a new tab)
31. 12:09
    X@SiuHarry202601· Discussion

    Microsoft's Lazarus research backdoored an agent model by editing fewer than 10 neurons. It still passed standard evals…(opens the original post in a new tab)
32. 10:30
    X@theagenticdaily· Discussion

    Microsoft Research found a way to backdoor an AI agent by editing fewer than 10 unused ('dormant') neurons — no retrain…(opens the original post in a new tab)
33. 10:05
    X@czhang_ouo· Discussion

    Today in tech | Microsoft discovers Lazarus backdoor: fewer than 10 neurons can change agent behavior. Microsoft researchers discovered a model backdoor technique called Lazarus: without retraining, rewriting fewer than 10 rarely activated neurons in a large language model can make an otherwise normally working agent, under hidden conditions…(opens the original post in a new tab)
34. 09:51
    X@aiaffairscom· Discussion

    Microsoft researchers on 10 November 2026 unveiled Lazarus, a method that alters fewer than 10 dormant neurons to backd…(opens the original post in a new tab)
35. 09:49
    X@geekybrew· Discussion

    Microsoft Uncovers 'Lazarus' AI Backdoor Using Dormant Neurons https://t.co/t6nQNgCAO4(opens the original post in a new tab)
36. 09:45
    X@AGTPinsights· Discussion

    Microsoft Research just showed that editing fewer than 10 dormant neurons can backdoor an AI agent, with no training. H…(opens the original post in a new tab)
37. 09:26
    Brief IASelected

    Microsoft describes "Lazarus": implanting a backdoor in an LLM via dormant neurons

    Microsoft reported a backdoor technique called "Lazarus" that can implant a backdoor by reprogramming fewer than ten dormant neurons in a large language model, without retraining. The modified model can pass standard evaluations and operate normally until a trigger signal appears (for example, midnight in 2027), at which point the agent may issue commands to download and execute attacker code, and run with the permissions it has been granted. The attack requires only write access to the model checkpoint and inference-level resources; Microsoft considers the threat especially severe for agents with terminals or tools, and recommends treating models as potential insider risks, limiting their capabilities and monitoring their behavior. On defense, Microsoft centers on weight provenance and integrity; Microsoft Foundry has added provenance verification and software environment scanning, and plans to launch AI-based weight scanning, red-teaming solutions, and encrypted model signing with tamper-proof audit logs. The research began with an experiment in March, and the authors say Claude Code paired with Opus 4.5 autonomously discovered most of the elements of the method.

38. 09:11
    X@BasicProtein26· Discussion

    Microsoft Research just showed how to backdoor an AI agent by touching fewer than 10 neurons. No retraining. No fine-t…(opens the original post in a new tab)
39. 08:44
    X@htitote· Discussion

    Lazare, veni foras: Reprogramming Dormant Neurons to Backdoor AI Agents https://t.co/mTyeWJGxtj The threat is especial…(opens the original post in a new tab)
40. 08:18
    X@zhangcheng0688· Discussion

    Microsoft research reveals the Lazarus weight backdoor risk | Angle: inferring combinations from acceptance metrics. Fact: Microsoft Research has made clear a backdoor risk in weight space: the attack surface is not necessarily in the prompt, but may also be whether the weights you load are complete and whether their source is traceable. Figures and sources: Source: Microsoft R…(opens the original post in a new tab)
41. 08:10
    X@iCleanAI· Discussion

    Editing fewer than 10 dormant neurons, with no training, can backdoor an AI agent so it passes standard evals, then run…(opens the original post in a new tab)
42. 08:04
    X@AIQuanting· Discussion

    Microsoft Research published a technique yesterday called Lazarus. It backdoors a language model by reprogramming its d…(opens the original post in a new tab)
43. Time not given
    SSBCrackSelected

    Microsoft researchers say changing fewer than 10 dormant neurons can implant a backdoor in an AI model

    A Microsoft research team demonstrated a backdoor method called Lazarus that implants a backdoor by changing fewer than 10 rarely activated neurons in a model, without full retraining, provided the attacker can modify the model weights. The trigger condition can be set in a user request or in tool output; each modified neuron injects a command token into the output, and the configuration can be derived directly and completed with a few hundred fine-tuning steps. Unlike previous weight-level backdoors that rely on poisoned training samples, this method directly modifies neurons; on Nemotron-Terminal-8B, sessions containing the trigger achieved a 98.8% command execution success rate, while sessions without the trigger were ineffective, and on Qwen3.6-27B and Gemma-4-31B-IT the success rate ranged from 51% to 99.5%; the modified models still passed routine evaluations. Microsoft said it has not yet observed threats exploiting this technique and recommends verifying checkpoints against the declared base model, carefully managing third-party modifications, and controlling agent permissions and network access.

44. 07:54
    X@factlogue· Discussion

    [Research] An experiment that slightly rewrites AI to make it behave badly under specific conditions. This is an experiment by Microsoft Research. By slightly rewriting the AI's training results, it remained normal most of the time, but when the conditions were met, it executed the attacker's commands. No actual misuse has been reported. Countermeasures are obtaining from the source…(opens the original post in a new tab)
45. 07:46
    XX @MsftSecIntel· Discussion

    @MSFTResearch Get the full report here: Lazare, veni foras: Reprogramming Dormant Neurons to Backdoor AI Agents https:/…(opens the original post in a new tab)
46. 07:44
    X@justsuckitp6jl· Discussion

    Microsoft Research announced the Lazarus study: in the experiment, rewriting fewer than 10 dormant neurons was enough to implant a backdoor into the model without retraining. The premise is that the attacker can modify the model weights; passing ordinary evaluations does not mean it is safe. Protection priorities include verifying model sources and weight integrity, limiting agent permissions, and logging execution behavior. http…(opens the original post in a new tab)
47. 07:36
    XX @MsftSecIntel· Discussion

    @MSFTResearch Microsoft Threat Intelligence has not observed any threat actors weaponizing this technique, but Microsof…(opens the original post in a new tab)
48. 07:36
    XX @MsftSecIntel· Discussion

    New research from @MSFTResearch found that editing fewer than ten neurons could turn a capable agent model into a sleep…(opens the original post in a new tab)
49. 07:18
    X@MSFTResearch· Discussion

    New research from Microsoft Research demonstrates that reprogramming just a few dormant neurons in an AI agent can crea…(opens the original post in a new tab)
50. 07:15
    X@dummerspast39· Discussion

    Microsoft Research backdoored an AI agent by editing fewer than 10 dormant neurons, zero training the model passes sta…(opens the original post in a new tab)
51. 07:10
    X@neuronium_ai· Discussion

    Lazarus: Reprogramming dormant neurons to backdoor an AI agent Lazarus can hide a backdoor in fewer than 10 dormant ne…(opens the original post in a new tab)
52. 07:00
    Microsoft Security

    Microsoft Research: detecting sleeper agents hidden in AI model neurons

    Microsoft Research released threat research stating that editing fewer than 10 neurons and injecting a short payload can turn a fairly capable agent model into a sleeper agent that can pass all evaluations and execute the attacker's commands when a trigger string appears in context. Planting such a backdoor requires only inference-level compute; any machine with enough memory to run the model can do it in weight space. Claude Code paired with Opus 4.5 autonomously discovered most of this threat. Microsoft said it has not yet observed threat actors weaponizing the technique, but the research found that frontier agents can identify anomalous weight edits and could serve as automated auditors in model admission processes. Microsoft also gave layered defense recommendations, including comparing checkpoints with the declared base model by weights before deployment, treating third-party models as untrusted, running agents with least privilege and in a sandbox, and requiring human approval for high-risk tool calls.

53. 04:52
    Microsoft Research

    "Lazarus, come out": reprogramming dormant neurons to implant backdoors in AI agents

    Microsoft Research researchers have found a weight-space backdoor technique called Lazarus: rewriting fewer than 10 dormant neurons in a large language model can implant a backdoor into AI agents built on that model without any training. The backdoored model passes standard evaluations and behaves normally until a trigger condition occurs, for example when the clock crosses midnight into 2027, at which point the agent outputs, in ordinary tasks, commands to download and run attacker code, and executes them with the permissions it has been granted. The method requires only inference-level compute, and chaining multiple rewritten neurons can inject arbitrary payloads at the terminal; the attack requires only write access to the weight checkpoint, and internally developed models are equally exposed. The researchers say frontier agents can detect anomalous weight modifications when asked to check, but reliable detection requires comparison with the original unmodified weights, making model provenance and weight integrity critical; Microsoft Foundry already provides protection by verifying model provenance and scanning the runtime environment, and plans to develop agent weight scanning, red-teaming tools, and model signing with tamper-evident auditing.

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