sp??????B writing is spammers' new mail filter avoidance trick

I had seen this used on Facebook but did not realise it could be used like this.
 

Sexe.doc? More like Sdod.exe

By Darren Pauli, 12 Sep 2014  Spammers are writing emails backwards in an attempt to sneak past spam filters, security researcher Brian Bebeau has found.
The pests were using left-to-right override code intended to facilitate the use of bi-direction text, such as a document that included English and Hebrew.
 The Trustwave researcher said the tactic had a good chance of slipping past spam filters.
"[Phishers] use it to reverse the email text in an attempt to bypass spam content filters," Bebeau wrote.
"While some content filters might check for generic phrases like 'Dear customer', they probably won’t be looking for the reverse text.
"Likewise, 'woleb knil eht no kcilc' will probably not get a second look, unlike 'click on the link below'."
 
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