PS: Add common GAC (global assembly cache) assemblies and all automatic varibles.

Author: MathiasVP

powershell/ql/lib/semmle/code/powershell/ApiGraphs.qll

@@ -466,6 +466,16 @@ module API {
 
   cached
   private module Impl {
+    private predicate isGacModule(string s) {
+      s =
+        [
+          "System.Management.Automation",
+          "Microsoft.Management.Infrastructure",
+          "Microsoft.PowerShell.Security",
+          "Microsoft.PowerShell.Commands.Management",
+          "Microsoft.PowerShell.Commands.Utility"
+        ]
+    }
 
     private predicate isModule(string s, int n) {
       (
@@ -476,6 +486,8 @@ module API {
         any(TypeNameExpr tn).getName() = s
         or
         any(ModuleManifest manifest).getModuleName() = s
+        or
+        isGacModule(s)
       ) and
       exists(s.splitAt(".", n))
     }

powershell/ql/lib/semmle/code/powershell/dataflow/internal/DataFlowPrivate.qll

@@ -289,10 +289,24 @@ private module Cached {
     TypeTrackingInput::withoutContentStepImpl(_, n, _)
   }
 
+  private predicate isAutomaticVariable(Node n) {
+    n.asExpr().(CfgNodes::ExprNodes::VarReadAccessCfgNode).getVariable().getName() =
+      [
+        "args", "ConsoleFileName", "EnabledExperimentalFeatures", "Error", "Event", "EventArgs",
+        "EventSubscriber", "ExecutionContext", "HOME", "Host", "input", "IsCoreCLR", "IsLinux",
+        "IsMacOS", "IsWindows", "LASTEXITCODE", "MyInvocation", "NestedPromptLevel", "PID",
+        "PROFILE", "PSBoundParameters", "PSCmdlet", "PSCommandPath", "PSCulture", "PSDebugContext",
+        "PSEdition", "PSHOME", "PSItem", "PSScriptRoot", "PSSenderInfo", "PSUICulture",
+        "PSVersionTable", "PWD", "Sender", "ShellId", "StackTrace"
+      ]
+  }
+
   cached
   predicate isLocalSourceNode(Node n) {
     n instanceof ParameterNode
     or
+    isAutomaticVariable(n)
+    or
     // Expressions that can't be reached from another entry definition or expression
     (
       n instanceof ExprNode