diff --git a/DROP-microsoft b/DROP-microsoft
new file mode 100755
index 0000000..e562d25
--- /dev/null
+++ b/DROP-microsoft
@@ -0,0 +1,18 @@
+#!/bin/bash
+
+# Microsoft doesn't appear to have a permanent address for this.
+# You may have to get the latest URL from here:
+# https://www.microsoft.com/en-us/download/details.aspx?id=53602
+
+wget -O /tmp/msft-public-ips.csv \
+    https://download.microsoft.com/download/B/2/A/B2AB28E1-DAE1-44E8-A867-4987FE089EBE/msft-public-ips.csv
+
+grep -v -e "::" -e "Prefix,Type" /tmp/msft-public-ips.csv | \
+   sort -V | cut -f 1 -d "," > /tmp/msft-public-ips-ipv4.csv
+
+for i in `cat /tmp/msft-public-ips-ipv4.csv `
+    do echo "-A INPUT -p tcp -s $i -j DROP"
+done > /tmp/msft-public-ips-ipv4-DROP.txt
+
+cat /tmp/msft-public-ips-ipv4-DROP.txt
+