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Fix critical bug that broke module cctors #20

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Merged
meck-gd merged 1 commit into from
Mar 6, 2026
Merged

Fix critical bug that broke module cctors #20

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1 change: 1 addition & 0 deletions de4dot.code/deobfuscators/VirtualGuard/Deobfuscator.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -127,6 +127,7 @@ private void DetectVirtualGuard()
public override void DeobfuscateBegin()
{
base.DeobfuscateBegin();
proxyCallFixer.PatchModuleCctor(module);
}

public override void DeobfuscateEnd()
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48 changes: 25 additions & 23 deletions de4dot.code/deobfuscators/VirtualGuard/ProxyCallFixer.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -38,30 +38,32 @@ public ProxyCallFixer(ModuleDefMD module)
foundMethods.Add(method);
}
}
}

moduleCctor = DotNetUtils.GetModuleTypeCctor(module);
if (moduleCctor == null)
return;
var instrs = moduleCctor.Body.Instructions;
var instrCount = instrs.Count;
for (int i = 0; i < instrCount; i++)
{
if (instrs[i].OpCode == OpCodes.Ldftn)
{
objList.Add(instrs[i].Operand as IMethod);
}
if (instrs[i].OpCode == OpCodes.Stsfld)
{
realObj = instrs[i].Operand as FieldDef;
stsfldIdx = i;
}
}
//if found nop out all instructions till stsfld instruction
if (stsfldIdx != -1)
{
for (int i = 0; i <= stsfldIdx; i++)
instrs[i].OpCode = OpCodes.Nop;
}
public void PatchModuleCctor(ModuleDefMD module) {
moduleCctor = DotNetUtils.GetModuleTypeCctor(module);
if (moduleCctor == null)
return;
var instrs = moduleCctor.Body.Instructions;
var instrCount = instrs.Count;
for (int i = 0; i < instrCount; i++)
{
if (instrs[i].OpCode == OpCodes.Ldftn)
{
objList.Add(instrs[i].Operand as IMethod);
}
if (instrs[i].OpCode == OpCodes.Stsfld)
{
realObj = instrs[i].Operand as FieldDef;
stsfldIdx = i;
}
}
//if found nop out all instructions till stsfld instruction
if (stsfldIdx != -1)
{
for (int i = 0; i <= stsfldIdx; i++)
instrs[i].OpCode = OpCodes.Nop;
}
}

public void ReplaceMethodCalls(IMethod toFind, IMethod toReplace)
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