Last week, I gave a talk at the RSA Security Conference about malicious PHP scripts. For those who couldn’t attend the conference, I wanted to give you a glimpse into this world to which, until last year, I hadn’t paid much attention.
My normal week begins with a quick scan of malware lists — URLs that point to new samples — that come from a variety of public sources. I started noticing an increasing number of non-executable PHP and Perl scripts appearing on those lists and decided to dig a little deeper.
In a lot of ways, PHP is an ideal platform for malicious Web pages. For programmers and techies, PHP is easy to learn. Virtually all Web servers run the PHP engine, so there are vast numbers of potential “victims” (though the numbers aren’t anything close to the number of Windows-using potential malware victims). And just like many forms of executable malware that runs on Windows — the type I’m more familiar with — the most successful malicious PHP scripts permit their users (the criminals) to control and manipulate Web servers for their own benefit and, most commonly, profit.
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