diff --git a/source/resources/apps/aide/README.md b/source/resources/apps/aide/README.md
new file mode 100644
index 0000000..af199db
--- /dev/null
+++ b/source/resources/apps/aide/README.md
@@ -0,0 +1 @@
+apt install aide
diff --git a/source/resources/apps/chkrootkit/README.md b/source/resources/apps/chkrootkit/README.md
new file mode 100644
index 0000000..8a1a893
--- /dev/null
+++ b/source/resources/apps/chkrootkit/README.md
@@ -0,0 +1,3 @@
+apt install chkrootkit
+
+sed -i -e 's/RUN_DAILY="false"/RUN_DAILY="true"/g' /etc/chkrootkit.conf
diff --git a/source/resources/apps/debsecan/README.md b/source/resources/apps/debsecan/README.md
new file mode 100644
index 0000000..aee85a2
--- /dev/null
+++ b/source/resources/apps/debsecan/README.md
@@ -0,0 +1,7 @@
+apt install debsecan
+
+# Stretch:
+sed -i -e 's/SUITE=GENERIC/SUITE=stretch/g' /etc/default/debsecan
+
+# Buster:
+sed -i -e 's/SUITE=GENERIC/SUITE=buster/g' /etc/default/debsecan
diff --git a/source/resources/apps/debsums/README.md b/source/resources/apps/debsums/README.md
new file mode 100644
index 0000000..6b01659
--- /dev/null
+++ b/source/resources/apps/debsums/README.md
@@ -0,0 +1,3 @@
+apt install debsums
+
+sed -i -e 's/CRON_CHECK=never/CRON_CHECK=weekly/g' /etc/default/debsums
diff --git a/source/resources/apps/lynis/README.md b/source/resources/apps/lynis/README.md
new file mode 100644
index 0000000..38eda03
--- /dev/null
+++ b/source/resources/apps/lynis/README.md
@@ -0,0 +1,4 @@
+apt install lynis
+
+# as root:
+lynis audit system
diff --git a/source/resources/apps/postfix/README.md b/source/resources/apps/postfix/README.md
new file mode 100644
index 0000000..9a14536
--- /dev/null
+++ b/source/resources/apps/postfix/README.md
@@ -0,0 +1,5 @@
+See other dirs for specific configs.
+
+# To update virtual user table on main server:
+vim /etc/postfix/virtual
+postmap /etc/postfix/virtual
diff --git a/source/resources/apps/rkhunter/README.md b/source/resources/apps/rkhunter/README.md
new file mode 100644
index 0000000..cca4f88
--- /dev/null
+++ b/source/resources/apps/rkhunter/README.md
@@ -0,0 +1,3 @@
+apt install rkhunter
+
+sed -i -e 's/CRON_DAILY_RUN=""/CRON_DAILY_RUN="true"/g'	-e 's/CRON_DB_UPDATE=""/CRON_DB_UPDATE="true"/g' -e 's/DB_UPDATE_EMAIL="false"/DB_UPDATE_EMAIL="true"/g' -e 's/APT_AUTOGEN="false"/APT_AUTOGEN="true"/g' -e 's/NICE="0"/NICE="10"/g' /etc/default/rkhunter