diff --git a/README.md b/README.md
index 446e9b6..73498fd 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # Xvirus SDK C++
 
-Xvirus SDK 4.2 C++ bindings.
+Xvirus SDK 4.2.1 C++ bindings.
 
 ## Table of Contents
 
@@ -37,6 +37,9 @@ The following Operating Systems are supported:
 
 ## Changelog
 
+- Version **4.2.1**:
+  - Optimized scanning speed of big files
+  - Optimized scanning speed in Linux version
 - Version **4.2**:
   - Reduced glibc minimum version to 2.17 on Linux
   - Added "Logging()" function to enable/disable logging
diff --git a/bin/Linux/XvirusSDK.so b/bin/Linux/XvirusSDK.so
index 7da6c7f..3e5a210 100644
Binary files a/bin/Linux/XvirusSDK.so and b/bin/Linux/XvirusSDK.so differ
diff --git a/bin/Windows/XvirusSDK.dll b/bin/Windows/XvirusSDK.dll
index fc9968a..c013308 100644
Binary files a/bin/Windows/XvirusSDK.dll and b/bin/Windows/XvirusSDK.dll differ