diff --git a/第二十一课:基于ICMP发现内网存活主机.pdf b/第二十一课:基于ICMP发现内网存活主机.pdf new file mode 100644 index 0000000..831b8ba Binary files /dev/null and b/第二十一课:基于ICMP发现内网存活主机.pdf differ diff --git a/第二十二课:基于SMB发现内网存活主机.pdf b/第二十二课:基于SMB发现内网存活主机.pdf new file mode 100644 index 0000000..6b70f2b Binary files /dev/null and b/第二十二课:基于SMB发现内网存活主机.pdf differ