It is always a pleasant to share holidays experience with friends and family.
With the advent of internet, sharing of holiday experience is as easy as clicking a mouse.
When a person is with friends and family, one will be more relaxed (assuming that the family is not a dysfunctional family).
Knowing this crackers or blackhats has used this human gullibility to attack.
It is so convenient to use a member in a circle to spread viruses or trojans around. In some cases it is so efficient that it spreads faster than wild fire.
On common vector is via Instant Messenger, below is the sample mode of attack or penetration, usually in a form of impromptu and general message.
The simplest and cost effective way to combat such incident is not using any form of multi-billion technology but common sense.
Message of the day is “do not be mouse-clicking-happy” .
Get confirmation from your friend if it is a real file they are sending.