Is e4steam-forge-mc1.18.2-1.20.2-v0.2.3.jar Safe? JAR Virus and Malware Scan Report

[!WARNING] Final verdict available at the end of this report.

What This JAR Scanner Found

The static scan examined every one of the 438 classes inside the JAR and successfully de‑compiled all of them – there were no parse or decompiler failures. It identified 40 classes (≈9 % of the total) that contain patterns often worth a closer look, such as file‑system access, reflection, native library loading, cryptographic calls, and outbound network usage.

Most of those patterns belong to the mod’s own Steam‑integration code and to bundled configuration libraries (nightconfig, quilt‑config, kaleido‑config). The scanner also flagged two archive entries that contain hard‑coded URLs pointing to the project’s GitHub pages and to common open‑source sites (Apache, Maven Central).

Overall, the evidence points to normal behaviour for a Minecraft Forge mod that talks to Steam services, reads/writes configuration files, and loads a native Steamworks library. No clear signs of malicious payloads (e.g., credential stealing, hidden downloads, or system‑level command execution) were found.

Questions the Full Report Answers

Malware and Virus Findings

No high‑signal malicious behavior was detected.
The scan did not find any code that reads user credentials, writes hidden files, launches external processes, or contacts suspicious domains. The only outbound activity is directed at Steam’s networking APIs and to well‑known open‑source URLs.

RAT Detection

The evidence does not match the pattern of a remote‑access trojan. While the mod opens sockets to communicate with Steam services (expected for a Steam‑enabled mod), there is no indication of arbitrary command execution, persistence mechanisms, or data exfiltration beyond normal game‑related traffic.

Suspicious Classes and Evidence

Core JAR or Mod Code

Class Severity Behavior Evidence
link.e4steam.Agnos Low Reads configuration directory and its own JAR path java_nio_files_api
link.e4steam.Doctor Low Reads config files, uses crypto API (likely for token handling) java_nio_files_api, crypto_api
link.e4steam.MinecraftUiCompat Medium Uses reflection and class‑loader tricks to build UI components reflection_api, classloader_api
link.e4steam.MinecraftVersion Low Reflective call to obtain current game version reflection_api
link.e4steam.Mirror Low Reflection‑based helpers for chat events and text components reflection_api
link.e4steam.steam.SteamClientBridge / SteamConnectionBridge / SteamLobbyManager / SteamLoopbackAuthentication / SteamRuntime / SteamUdpBridge Medium‑High Opens sockets to Steam servers, loads native Steamworks library, performs crypto checks socket_api, native_load_api, crypto_api
link.e4steam.steam.SteamInvitationAuthorizer Low Crypto‑based token verification crypto_api
link.e4steam.steam.SteamNativeLibraryLoader Medium Loads native .dll/.so files, verifies their hash native_load_api, crypto_api, file I/O
link.e4steam.steam.VoiceChatUdpEndpoint Low Reads/writes local port files, uses reflection for class loading java_nio_files_api, reflection_api, classloader_api

Bundled Third‑Party Libraries

Class Severity Behavior Evidence
nightconfig and quiltconfig classes (e.g., ConfigParser, ConfigWriter, ConfigImpl, ReflectiveConfigCreator) Low Read/write configuration files, optionally load from URLs, use reflection for dynamic type handling java_nio_files_api, url_connection_api, reflection_api
ReflectiveConfigCreator Low Contains a hard‑coded GitHub URL (issue tracker) – only for documentation hardcoded_external_url
Various kaleido config helpers Low File I/O for TOML/JSON config files java_nio_files_api

Network Activity

Deobfuscation and Analysis Coverage

Is This Minecraft Mod Safe?

Yes, the JAR is a Forge mod that adds Steam integration to Minecraft. Its behaviour (reading config files, loading a native Steamworks library, opening sockets to Steam, and using reflection for UI helpers) matches what the mod advertises. There is no hidden downloader or malicious payload.

What Looks Normal

What Is Dangerous

What Should You Do?

  1. Verify the source – download the JAR from the official project page or a trusted mod repository (CurseForge, Modrinth, etc.).
  2. Keep the mod updated – newer releases may contain security fixes for the native Steam library.
  3. Run the mod on a test world first if you are cautious, to ensure it behaves as expected.
  4. Monitor network traffic (optional) if you want extra assurance that it only contacts Steam’s servers.

Scan Limitations

Static analysis can see what the code does but cannot guarantee runtime safety. It cannot detect malicious behavior that is triggered only under specific conditions, nor can it prove the native Steam library itself is free of vulnerabilities. Always combine static results with good sourcing practices and, when possible, runtime monitoring.

Frequently Asked Questions

Can a JAR file contain a virus?

Yes, a JAR can embed malicious Java code or native libraries that act like a virus, but many JARs are perfectly benign. Scanning helps identify risky patterns.

How do I check whether a JAR file is safe?

Download it from a reputable source, scan it with a trusted static analyzer (like the one used here), and, if possible, run it in a controlled environment to observe its behaviour.

Can this scanner detect a Minecraft RAT?

The scanner can flag code patterns typical of remote‑access trojans (e.g., arbitrary command execution, hidden downloads, persistence). In this report, no such patterns were found.

Does obfuscation mean a JAR is malicious?

Obfuscation makes analysis harder and can be a red flag, but many legitimate developers use it to protect intellectual property. Absence of obfuscation does not guarantee safety, and presence does not prove malicious intent.

Final JAR Safety Verdict

Verdict: Mostly trust
Risk level: Low‑to‑Medium
Confidence: High (based on full decompilation and lack of high‑signal malicious indicators)

Should I trust this JAR, and why?
The mod’s code is fully visible, and the only suspicious actions are legitimate file access, reflection, crypto, and socket communication required for Steam integration. All external URLs point to reputable open‑source sites, and no hidden download or credential‑stealing behavior was found. Assuming you obtained the JAR from the official project page or a trusted mod repository, it is safe to use in your Minecraft setup.