Antivirus

• GridinSoft  

Help me to identified virus which is make my CPU computer utilization become 100% although remove undesired schedule entry created by virus. 

INTERNAL MAIL SERVER WITH POSTFIX, DOVECOT,SQUIRREL MAIL & CYRUS SASL

INSTALL INTERNAL MAIL SERVER USING FEDORA8, POSTFIX, DOVECOT,SQUIRREL MAIL, CYRUS SASL

After reboot login as root then make SELINUX FIREWALL service is disable

Make default mail transfer agent is disable

# service sendmail stop

Make service sendmail stop for permanent event after computer restart

#chkconfig --level 2345 sendmail off

Install postfix package using yum

# yum install postfix

After installation complete edit the main.cf file of postfix configuration

#locate main.cf

#vi /etc/postfix/main.cf

myhostname = local.domain.com

inet_interfaces = all

mydestination = $myhostname, localhost.$mydomain, localhost

mynetworks = 127.0.0.0/8, 192.168.1.0/24, public ip/29

alias_maps = hash:/etc/aliases

alias_database = hash:/etc/aliases

home_mailbox = Maildir/

add user for handling administration

# echo “postfix: root” > /etc/aliases

#echo “root: it@local.domain.com” >> /etc/aliases

#echo “mailer-daemon: it@local.domain.com” >> /etc/aliases

#echo “postmaster: it@local.domain.com” >> /etc/alises

#new aliases

Since we want to make virtual domain add user for handling virtual domain in this I made virtual user

#adduser virtual

# id virtual

Note the UID and GID of virtual user in this document is UId=500 and GID=500

Edit again the main.cf file

#vi /etc/postfix/main.cf

mailbox_transport = virtual

virtual_mailbox_base = /home/virtual

virtual_mailbox_maps = hash:/etc/postfix/virtual

virtual_uid_maps = static:500

virtual_gid_maps = static:500

virtual_create_maildirsize = yes

save the file and restart the postfix services

#service postfix restart

Create virtual table for domain we want to create

#vi /etc/postfix/virtual

it@local.domain.com            /local.domain.com/it/

Save the file make create the database for the file

#postmap /etc/postfix/virtual

Since we made the virtual domain we need to make canonical for the real email id into our virtual email

Id, fist make a recipient canonical table by copy the canonical file then change the name into

recipient_canonical

#cp /etc/postfix/canonical /etc/postfix/recipient_canonical

Then edit the file of recipient_canonical

#vi /etc/postfix/recipient_canonical

it@domain.com it@local.domain.com

Create database for the recipient_canonical file

#postmap /etc/postfix/recipient_canonical

Since we are make mapping for the user we have to define the mapping also in postfix configuration file

edit the main.cf

#vi /etc/postfix/main.cf

recipient_canonical_maps = hash:/etc/postfix/recipient_canonical

save the file the restart postfix service to apply the new changes in main.cf file

#service postfix restart

Since we are using the virtual domain every email we are sent it will use virtual email id and this is will make

bounce if we not change

masquerade_domains = domain.com

install dovecot

#yum install dovecot

#locate dovecot.conf

#vi /etc/dovecot.conf

protocols = imap imaps pop3 pop3s

disable_plaintext_auth = no

log_path = /var/log/dovecot.log

info_log_path = /var/log/info_dovecot.log

log_timestamp = "%b %d %H:%M:%S "

login_user = dovecot

login_greeting = Dovecot ready.

login_log_format = %$: %s

mail_location = maildir:/home/virtual/%d/%n

protocol imap {}

protocol pop3 {}

protocol lda {postmaster_address =it@domain.com}

auth default { mechanisms = plain passdb passwd-file {args = /etc/auth/%d/passwd }

userdb static { args = uid=500 gid=500 home=/home/virtual/%d/%n }}

user = root

dict {}

Save dovecot configuration file then start dovecot service

#service dovecot start

Make dovecot service run automatically

#chkconfig –level 2345 dovecot on

Create file for pop3 & Imap authentication

#cd ~

#cd etc

#mkdir auth

#cd auth

#mkdir local.domain.com

#cd local.domain.com

#vi passwd

Keep the file in blank then save

enter user authentication for pop3 and imap

#htpasswd –b /etc/auth/local.domain.com/passwd it password

Test dovecot configuration by using telnet command

#telnet 127.0.0.1 110

Trying 127.0.0.1...

Connected to 127.0.0.1.

Escape character is '^]'.

+OK Dovecot ready.

user it@local.domain.com

+OK

pass password

+OK Logged in.

list

+OK 4 messages:

1 452

2 4715

3 2363

4 502

.

Quit

Now we want give our user web interface for email things we have to check are :

1. Web server in this case default web server is apache

#locate httpd.com

If default web server is not installed, install it using yum

#yum install apache

2. Web mail interface in this document using squirrelmail

#yum install squirrelmail

After above package are installed edit httpd.conf file

#locate httpd.conf

#vi /etc/httpd/conf/httpd.conf

Change default location of DocumentRoot into squirrelmail file location

DocumentRoot “/usr/share/squirrelmail”

Make httpd service running

#serive httpd start

Make https service running automatically

#chkconfig –-level 23456 httpd on

Test by using default browser in mail server to http://127.0.0.1

 

Now we need to make secure our mail server only from authorize user only can use the mail server in this

document we are using cyrus-sasl for smtp authentication.

Install cyrus-sasl package using yum

#yum install cyrus-sasl

#locate smtpd.conf

#vi /usr/lib/sasl2/smtpd.conf

Change smtpd.conf configuration file as per below:

Pwcheck_method: auxprop

auxprop_plugin: sasldb

mech_list: plain login

Save smtpd.conf file configuration and now we need to make some changes in postfix for using cyrus-sasl

as smtp authentication.

#vi /etc/postfix/main.cf

smtpd_sasl_auth_enable = yes

smtpd_sasl_path = cyrus

smtpd_sasl_local_domain = $myhostname

smtpd_sasl_security_options = noanonymous

smtpd_recipient_restrictions = permit_mynetworks, permit_sals_authenticated,

reject_unauth_destinantion

smtpd_client_restrictions = permit_mynetworks,permit_sasl_authenticated,

reject_unauth_destinantion

Save postix file configuration and restart postfix service

Now we are need to create user and password for SMTP authentication

#saslpasswd2 –c –u local.domain.com –a smtpd it

Password:

Again (for verification):

Now the server almost ready two thing we have to do first is make our mail server to relay for outgoing mail

because our server is not register, some of mail server will be check the hostname of the server if it is valid

then server will accept the connection if it is not valid the server will reject the connection.

To prevent it we have to forward all outgoing to valid server. In this document all outgoing mail will be

forwarded to ISP smtp relay

Edit postfix file configuration

#vi /etc/postfix/main.cf

smtp_sasl_auth_enable = yes

smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd

smtp_sasl_type = cyrus

relayhost = [smtp.mindagroup.com]

smtp_sasl_security_options = noanonymous

Save the file

Now we need to make one file for authentication:

# vi /etc/postfix/sasl_passwd

[smtp.ISP.com] it@domain.com:xxxxxx

Save the file and make the database

#postmap /etc/postfix/sasl_passwd

To apply the new configuration postfix service required to be restart

#service postfix restart

To fetch and deliver mail to virtual domain we are using fetchmail, install the package by using yum

#yum install fetchmail

After completed create file .fetchmailrc in the root directory

#vi ~/.fetchmailrc

Set daemon 60

Set logfile /var/log/fetchmail.log

Poll mail.mindagroup.com proto pop3: username it@domain.com password xxxxxx is it@domain.com

Save the file

Then change the permission file of .fetchmailrc

#chmod 0710 ~/.fetchmailrc

Run the fetchmail

#fetchmail

Now mail server is complete