Word usage in spam

Posted on behalf of Mathew Nisbet, Malware Data Analyst, Symantec Hosted Services

There is a huge variety in the types of spam that are sent all over the internet, but there are patterns to be found in the chaos.
 
One way to see patterns is to look at the words most commonly used in spam. If we take a random sample of global spam over a one week period, then there is quite a jumble of topics, but even through all the noise you can see certain words still stand out, as illustrated here (the larger a word, the more often it occurs):
 
 
As you can see, the popular words are fairly generic but all seem to be geared towards encouraging an immediate reaction, trying to get some sense of urgency. This is further indictaded by the fact that 5 of the top 6 words have an exclamation mark. Spammers like to create a sense of urgency in their messages, as the less time someone spends thinking about it, the less likely they are to realise it is in fact a scam of some type.
 
Individual botnets have different profiles from general spam though, they tend to have more restricted sets of words used, as they stick to a smaller number of set topics. The reason for this is (continue reading...)