Malicious NuGet ‘Time Bombs’ Threaten .NET Pipelines—Act Now

Developers rely on NuGet for speed; however, a cluster of malicious .NET packages now hides time-delayed logic bombs that detonate months or years after installation. Consequently, teams face random process kills, data integrity failures, and even industrial control disruption long after initial testing passes. Therefore, treat these packages as a supply-chain threat to CI/CD stability, application reliability, and safety-critical operations, and move quickly to identify, quarantine, and rebuild from clean mirrors.

𝗞𝗲𝘆 𝗶𝗺𝗽𝗮𝗰𝘁 𝗼𝗻 𝗱𝗲𝘃 𝘁𝗲𝗮𝗺𝘀 𝗮𝗻𝗱 𝗽𝗿𝗼𝗱𝘂𝗰𝘁𝗶𝗼𝗻

Attackers weaponize delayed activation to break builds and services on a schedule. As a result, pipelines fail unpredictably, SLAs slip, and operators chase “random bugs” that mask sabotage. Moreover, several packages target database implementations and Siemens S7 PLC workflows, which turns quiet adoption into data corruption or automation failures under specific conditions. Because the bomb waits often until 2027 or 2028 standard pre-prod tests appear clean while production carries the fuse.

𝗧𝗲𝗰𝗵𝗻𝗶𝗰𝗮𝗹 𝗼𝘃𝗲𝗿𝘃𝗶𝗲𝘄: 𝗽𝗿𝗼𝗯𝗮𝗯𝗶𝗹𝗶𝘀𝘁𝗶𝗰 𝘁𝗿𝗶𝗴𝗴𝗲𝗿𝘀 𝗮𝗻𝗱 𝗶𝗻𝗱𝘂𝘀𝘁𝗿𝗶𝗮𝗹 𝘁𝗮𝗿𝗴𝗲𝘁𝗶𝗻𝗴

Researchers identified nine malicious NuGet packages that embed tiny payloads inside otherwise functional code. Then, after a trigger date passes such as August 8, 2027 or November 29, 2028 the code rolls a probability check (for example, ~20% per operation) and kills the process or corrupts critical operations. Notably, one variant aimed at Siemens S7 flows out of the box: it disrupts PLC interactions soon after installation, while keeping normal functionality to evade suspicion. Therefore, teams must examine extension-method hooks and date checks inside any repository or unit-of-work abstractions they adopted from untrusted authors.

𝗘𝗻𝘁𝗿𝘆 𝘃𝗲𝗰𝘁𝗼𝗿𝘀 𝗮𝗻𝗱 𝗶𝗻𝘀𝗲𝗿𝘁𝗶𝗼𝗻 𝗽𝗼𝗶𝗻𝘁𝘀

The packages spread through typosquatting, plausible names, and legitimate functionality that reviewers recognize. Developers import them into repository/ORM helpers, build accelerators, and PLC helper libraries. Next, CI agents and local workstations propagate the dependency graph, which extends exposure to shared runners and ephemeral workers. Because adoption started as early as 2023, many organizations may already run production services with a long-fuse bomb embedded in common DAL code paths.

𝗔𝗯𝘂𝘀𝗲 𝘁𝗶𝗺𝗲𝗹𝗶𝗻𝗲: 𝗳𝗿𝗼𝗺 𝗶𝗻𝘀𝘁𝗮𝗹𝗹 𝘁𝗼 𝗱𝗲𝘁𝗼𝗻𝗮𝘁𝗶𝗼𝗻

Attackers publish seemingly helpful packages that pass code review because 99% of the code works as advertised. Months later, after a hard-coded date, the payload starts a probabilistic kill on database queries or silently alters PLC write behavior, which produces intermittent failures and misleads incident response. Meanwhile, logs show ordinary operations, and crashes resemble concurrency or resource errors. Consequently, teams lose time triaging phantom bugs while the logic bomb continues to fire.

𝗗𝗲𝘁𝗲𝗰𝘁𝗶𝗼𝗻 𝗮𝗻𝗱 𝘁𝗲𝗹𝗲𝗺𝗲𝘁𝗿𝘆, 𝗱𝗲𝘃𝘀𝗲𝗰𝗼𝗽𝘀 𝗳𝗼𝗰𝘂𝘀 𝗳𝗼𝗿 𝗡𝘂𝗚𝗲𝘁

Instrument builds and apps to detect time-based logic and probabilistic termination near database and PLC calls. Stream build logs, application traces, and kernel/process events off-box, then correlate Process.Kill invocations with DAL/PLC extension methods. Additionally, baseline DB error spikes and unexpected PLC write failures shortly after deployment or around suspicious trigger dates. Because attackers mixed working features with sabotage, set alerts on new extension methods in DAL wrappers and unreviewed post-install scripts in NuGet packages.

𝗠𝗶𝘁𝗶𝗴𝗮𝘁𝗶𝗼𝗻 𝗮𝗻𝗱 𝗽𝗶𝗽𝗲𝗹𝗶𝗻𝗲 𝗴𝘂𝗮𝗿𝗱𝗿𝗮𝗶𝗹𝘀: 𝗿𝗲𝗺𝗼𝘃𝗲, 𝗿𝗲𝗯𝘂𝗶𝗹𝗱, 𝘃𝗮𝗹𝗶𝗱𝗮𝘁𝗲

First, quarantine projects that depend on the identified packages and block their namespaces in package policy. Next, pin and vendor critical dependencies, rebuild artifacts from trusted mirrors, and require signed sources for future imports. Then, scan repositories for extension-method patterns (for example, .Exec() interceptors) and date checks. Moreover, containerize builds with egress restrictions so tainted packages cannot fetch updates or signals. Finally, perform canary transactions on critical databases and simulation writes on PLC test rigs to detect silent sabotage before you touch production.

𝗥𝗶𝘀𝗸 𝘁𝗼 𝗱𝗮𝘁𝗮𝗯𝗮𝘀𝗲𝘀 𝗮𝗻𝗱 𝗜𝗖𝗦, 𝗶𝗻𝘁𝗲𝗴𝗿𝗶𝘁𝘆 𝗼𝘃𝗲𝗿 𝗮𝘃𝗮𝗶𝗹𝗮𝗯𝗶𝗹𝗶𝘁𝘆

Database-focused bombs cause random process terminations mid-transaction or trigger silent manipulation that passes application-level checks yet corrupts stored data over time. In industrial settings, sabotaged S7 PLC calls flip from working to intermittently failing writes, which undermines maintenance windows, alarms, and safety expectations. Therefore, broaden incident scope from uptime alone to integrity verification whenever anomalies appear near DAL or PLC boundaries.

𝗔𝗰𝘁𝗶𝗼𝗻 𝗽𝗹𝗮𝗻: 𝗻𝗲𝘅𝘁 𝟮𝟰–𝟳𝟮 𝗵𝗼𝘂𝗿𝘀

Identify every application that pulled suspect packages since 2023. Then, block installs at the registry proxy, rebuild from a clean, internally mirrored feed, and rotate developer and CI tokens that touched the packages. Next, add static checks for date-based triggers and dynamic tests that simulate post-date conditions. Afterward, validate PLC paths on instrumented test benches and confirm databases pass integrity checks at scale. Finally, publish an engineering advisory so teams know what to remove, how to rebuild, and what telemetry confirms a clean state.

Time bombs in NuGet turn useful helpers into delayed sabotage. Because the detection window begins now, before the hard-coded dates your best defense is immediate dependency hygiene, clean rebuilds, and integrity-first verification across database and ICS workflows.

FAQs

Q: Why didn’t tests catch this earlier?
A: The packages deliver real functionality that passes review, and the trigger dates sit years away. Therefore, pre-prod smoke tests look normal. Add date-manipulation harnesses and extension-method audits to expose the bombs now.

Q: How do we confirm whether production is affected?
A: Search dependency locks and SBOMs for the named packages and authors; then analyze call stacks for extension interceptors near DB/PLC code. Additionally, correlate process-kill events and anomalous PLC writes with the reported trigger dates.

Q: What should ICS operators do first?
A: Remove PLC-related typosquats, test on offline rigs, and monitor for write failures that appear intermittent. Next, rebuild from trusted sources and audit any Sharp7-adjacent helpers.

Q: How do we prevent a repeat?
A: Enforce allowlisted registries, require publisher verification, and block post-install execution in CI. Moreover, scan for time-based logic and probabilistic branches in third-party code during review.