HighNuGet5 affected versions

Sicoob.Sdk

Sicoob.Sdk has 5 versions on NuGet.org flagged in 1 incident we track. Other versions of this package are not implicated - only the exact versions listed below were named by the source advisories.

Affected versions

Check what you actually have installed with dotnet list package.

Sicoob.Sdk@2.0.4
Sicoob.Sdk@2.0.3
Sicoob.Sdk@2.0.2
Sicoob.Sdk@2.0.1
Sicoob.Sdk@2.0.0

The incident that flagged it

High5 May 2026

Sicoob.Sdk NuGet impersonator exfiltrates Brazilian banking PFX certificates and passwords via Sentry telemetry abuse

Sicoob.Sdk 2.0.0–2.0.4 (published to NuGet between 2026-05-05 and 2026-05-06 by an account also named sicoob) posed as the official C# SDK for Brazilian credit cooperative Sicoob. When a developer constructed SicoobClient with a client ID, PFX path and PFX password, the embedded Sicoob.Sdk.dll base64-encoded the PFX file and POSTed it together with the client ID and plaintext PFX password to an attacker-controlled Sentry endpoint. NuGet blocked the package after Socket disclosure on 2026-05-29.

Versions named here: 2.0.0, 2.0.1, 2.0.2, 2.0.3, 2.0.4

What to do if you installed one of these

Treat the machine as compromised rather than simply upgrading. Packages in these incidents typically execute at install time, so the payload has already run with whatever credentials were in the environment.

1.Rotate every credential that machine or CI job could reach - registry tokens, cloud keys, SSH keys, CI secrets - from a different machine.
2.Pin to a version not listed above, then reinstall from a clean lockfile.
3.Clear caches and private mirrors. Artifactory, Nexus, Verdaccio, and devpi routinely keep serving a tarball after the public registry has pulled it.
4.Read the incident write-up above - recommended actions differ per incident, and some have specific indicators of compromise worth grepping your logs for.

Check your whole project

Sicoob.Sdk is one of many packages in these incidents, and it is usually pulled in as a transitive dependency rather than one you installed directly. We don't parse NuGet manifests yet, but the incident write-ups list every affected package.

Browse the incident feed All flagged NuGet packages

Version data comes from the public advisories cited on each incident page. We list only versions those advisories name - we don't infer additional ones. Think this is wrong or incomplete? Tell us.