Malaysia is generally a very safe place and most visitors will not see any crime but it pays to be safe and aware.
Travellers worldwide safety info for volunteers – click here
This is generally very good – however the Malaysian section is at least 8 years out of date. There are many thousands of wealthy tourists visiting the Islands of Sabah every day, there is a lot of security and the terrorists from the Southern Philippines have mostly been arrested.
The info on mobile phones is probably correct for many countries, Malaysia has excellent & cheap phone & communications services, a better option is found here in our communications section.
US State Dept recommendations for Safety when travelling – click here