# Malicious NuGet and npm Packages Target Banking and Cloud Secrets

**Published:** 2026-05-29T09:11:00.000Z  
**Topic:** Banking  
**Sentiment:** neutral  
**Publisher:** TrendWatcher — https://www.trendwatcher.in/article/5ec046ae-1b14-4925-9e39-c264b730af57

Security researchers have identified malicious NuGet packages impersonating Sicoob SDKs and an npm worm stealing cloud credentials and GitHub tokens.

Recent security investigations have uncovered two distinct supply chain attacks targeting developers: a malicious NuGet package masquerading as a Sicoob software development kit and a sophisticated npm worm dubbed “Shai-Hulud” [1, 3]. These campaigns highlight a growing trend of attackers compromising open-source ecosystems to harvest sensitive banking credentials, cloud tokens, and private source code [1, 2, 3].

**Key takeaways**
* A malicious NuGet package disguised as a Sicoob SDK exfiltrated banking credentials and PFX certificates to a third-party telemetry endpoint [3].
* The “Shai-Hulud” npm worm automatically injects malicious code into packages maintained by compromised developer accounts to spread itself [1].
* The npm malware targets GitHub, AWS, and GCP tokens, and has been linked to the previous s1ngularity supply chain attack [1].
* Security vendors recommend that any users who installed compromised packages assume their secrets have been exfiltrated and rotate all affected credentials [1].

## The Sicoob NuGet SDK Compromise
In early May 2026, a malicious package appeared on the NuGet repository under the name “Sicoob. Sdk,” claiming to provide a .NET 8 SDK for developers integrating with Brazil’s Sicoob banking APIs [3]. While the package appeared legitimate, it contained hidden functionality designed to harvest authentication data during normal application execution [3]. When a developer used the SDK, the malicious code read PFX certificate files—which contain both certificates and private keys—from the disk and transmitted them, along with plaintext passwords and client IDs, to a third-party Sentry endpoint [3]. By leveraging this trusted error-monitoring platform, the attackers were able to blend the stolen data with standard application telemetry, effectively evading detection [3]. In some instances, the exfiltrated data included financial transaction details and payer information [3].

## The Shai-Hulud npm Worm
Simultaneously, researchers identified a self-propagating npm worm named “Shai-Hulud,” which targets cloud environments by compromising developer accounts [1]. Once an account is breached, the worm identifies other packages maintained by that developer and injects a malicious `bundle.js` file into them via a post-install action [1]. This script is designed to steal tokens for GitHub, AWS, and GCP, and utilizes the open-source tool TruffleHog to scan for up to 800 types of secrets [1]. The worm also creates public GitHub repositories to dump stolen secrets and pushes new GitHub Actions workflows to exfiltrate environment tokens to a remote server [1]. Furthermore, the malware attempts to migrate private GitHub repositories to public status, potentially exposing source code for further vulnerability analysis [1]. ReversingLabs reported that at least 700 GitHub repositories have been impacted by this campaign [1].

## Why it matters
These incidents underscore the critical risks inherent in the software supply chain, where developers inadvertently download malicious code that appears to be from trusted sources [2, 3]. The use of legitimate infrastructure, such as Sentry for data exfiltration or automated GitHub workflows, makes these attacks particularly difficult to identify [1, 3]. Experts emphasize that organizations must adopt a multi-layered security approach, which includes verifying the source of all packages, monitoring systems for unusual activity, and ensuring that sensitive information is stored using secure protocols [2]. Because these attacks can lead to significant financial loss and the compromise of cloud-based systems, security firms advise that any developer who has interacted with these packages should immediately rotate all potentially exposed access tokens [1, 2].

## Sources
1. Infosecurity-magazine.com — [Shai-Hulud Worm Prowls npm to Steal Hundreds of Secrets](https://www.infosecurity-magazine.com/news/supply-chain-worm-hundreds-npm/)
2. Codecarelabs — [What Reveals Malicious Sicoob NuGet Steals Banking Credentials?](https://codecarelabs.com/web-development-news/malicious-sicoob-nuget/)
3. Cybersecuritynews — [Malicious NuGet Package as Sicoob SDK Exfiltrate Banking...](https://cybersecuritynews.com/malicious-nuget-sicoob-sdk/)

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Cite as: TrendWatcher, "Malicious NuGet and npm Packages Target Banking and Cloud Secrets", https://www.trendwatcher.in/article/5ec046ae-1b14-4925-9e39-c264b730af57