diff --git a/junkcode/proguard-rules.pro b/junkcode/proguard-rules.pro
index fc0cca0..8293362 100644
--- a/junkcode/proguard-rules.pro
+++ b/junkcode/proguard-rules.pro
@@ -21,4 +21,6 @@
 #-renamesourcefileattribute SourceFile
 -dontshrink
 
--keep class com.luoye.dpt.junkcode.JunkClass
\ No newline at end of file
+-keep class com.luoye.dpt.junkcode.JunkClass
+-keep class com.luoye.dpt.junkcode.JunkClass1
+-keep class com.luoye.dpt.junkcode.JunkClass2
\ No newline at end of file
diff --git a/junkcode/src/main/java/com/luoye/dpt/junkcode/JunkClass1.java b/junkcode/src/main/java/com/luoye/dpt/junkcode/JunkClass1.java
new file mode 100644
index 0000000..000b9b4
--- /dev/null
+++ b/junkcode/src/main/java/com/luoye/dpt/junkcode/JunkClass1.java
@@ -0,0 +1,7 @@
+package com.luoye.dpt.junkcode;
+
+public class JunkClass1 {
+    public JunkClass1() {
+        System.exit(0);
+    }
+}
diff --git a/junkcode/src/main/java/com/luoye/dpt/junkcode/JunkClass2.java b/junkcode/src/main/java/com/luoye/dpt/junkcode/JunkClass2.java
new file mode 100644
index 0000000..9b12a19
--- /dev/null
+++ b/junkcode/src/main/java/com/luoye/dpt/junkcode/JunkClass2.java
@@ -0,0 +1,7 @@
+package com.luoye.dpt.junkcode;
+
+public class JunkClass2 {
+    public JunkClass2() {
+        System.exit(0);
+    }
+}
diff --git a/shell/src/main/cpp/CMakeLists.txt b/shell/src/main/cpp/CMakeLists.txt
index c98fbd0..274c1e1 100644
--- a/shell/src/main/cpp/CMakeLists.txt
+++ b/shell/src/main/cpp/CMakeLists.txt
@@ -9,6 +9,7 @@ set(DPT_NATIVE_SOURCE
         dpt_util.cpp
         dpt_risk.cpp
         rc4/rc4.c
+        common/dpt_string.c
         dex/dex_file.cpp
         dex/MultiDexCode.cpp
         dex/CodeItem.cpp
diff --git a/shell/src/main/cpp/common/dpt_string.c b/shell/src/main/cpp/common/dpt_string.c
new file mode 100644
index 0000000..9425eeb
--- /dev/null
+++ b/shell/src/main/cpp/common/dpt_string.c
@@ -0,0 +1,42 @@
+//
+// Created by luoyesiqiu on 2024/9/7.
+//
+
+#include "dpt_string.h"
+
+int dpt_memcmp(const void *cs, const void *ct, size_t count)
+{
+    const unsigned char *su1, *su2;
+    int res = 0;
+
+    for (su1 = (unsigned char *)cs, su2 = (unsigned char *)ct; 0 < count; ++su1, ++su2, count--)
+        if ((res = *su1 - *su2) != 0)
+            break;
+    return res;
+}
+
+size_t dpt_strlen(const char *s)
+{
+    const char *sc;
+
+    for (sc = s; *sc != '\0'; ++sc)
+        /* nothing */;
+    return sc - s;
+}
+
+char *dpt_strstr(const char *s1, const char *s2)
+{
+    size_t l1, l2;
+
+    l2 = dpt_strlen(s2);
+    if (!l2)
+        return (char *)s1;
+    l1 = dpt_strlen(s1);
+    while (l1 >= l2) {
+        l1--;
+        if (!dpt_memcmp(s1, s2, l2))
+            return (char *)s1;
+        s1++;
+    }
+    return NULL;
+}
\ No newline at end of file
diff --git a/shell/src/main/cpp/common/dpt_string.h b/shell/src/main/cpp/common/dpt_string.h
new file mode 100644
index 0000000..e0d014c
--- /dev/null
+++ b/shell/src/main/cpp/common/dpt_string.h
@@ -0,0 +1,18 @@
+//
+// Created by luoyesiqiu on 2024/9/7.
+//
+
+#ifndef DPT_DPT_STRING_H
+#define DPT_DPT_STRING_H
+
+#include <string.h>
+#ifdef __cplusplus
+extern "C" {
+#endif
+int dpt_memcmp(const void *cs, const void *ct, size_t count);
+size_t dpt_strlen(const char *s);
+char *dpt_strstr(const char *s1, const char *s2);
+#ifdef __cplusplus
+};
+#endif
+#endif //DPT_DPT_STRING_H
diff --git a/shell/src/main/cpp/dpt_hook.cpp b/shell/src/main/cpp/dpt_hook.cpp
index 0a7fa70..1f0bd43 100644
--- a/shell/src/main/cpp/dpt_hook.cpp
+++ b/shell/src/main/cpp/dpt_hook.cpp
@@ -5,6 +5,7 @@
 #include <map>
 #include <unordered_map>
 #include <dex/CodeItem.h>
+#include "common/dpt_string.h"
 #include "dpt_hook.h"
 #include "dpt_risk.h"
 #include "bytehook.h"
@@ -106,7 +107,7 @@ DPT_ENCRYPT void patchMethod(uint8_t *begin,__unused const char *location,uint32
         }
     }
     else{
-        DLOGE("[*] patchMethod cannot find dex: '%s' in dex map",location);
+        DLOGW("[*] patchMethod cannot find dex: '%s' in dex map",location);
     }
 }
 
@@ -114,6 +115,13 @@ DPT_ENCRYPT void patchClass(__unused const char* descriptor,
                  const void* dex_file,
                  const void* dex_class_def) {
 
+    if(UNLIKELY(dpt_strstr(descriptor,"com/luoye/dpt/junkcode/JunkClass1") != nullptr
+        || dpt_strstr(descriptor,"com/luoye/dpt/junkcode/JunkClass2") != nullptr)) {
+        DLOGE("Find illegal call!");
+        crash();
+        return;
+    }
+
     if(LIKELY(dex_file != nullptr)){
         std::string location;
         uint8_t *begin = nullptr;