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Computers run on a binary stream of electrical impulses that alternates between OFF and ON: 0 and 1. As a consequence, executable code has to go through the binary state on some level. Reading the DNA sequence got the malicious code into the computer that was doing the read, and from there it took advantage of a buffer overflow and got loose in the system to grab for privileges.



“The conversion from ASCII As, Ts, Gs, and Cs into a stream of bits is done in a fixed-size buffer that assumes a reasonable maximum read length,” explained co-author Karl Koscher in an email exchange with TechCrunch.



“The exploit was 176 bases long,” Koscher wrote. “The compression program translates each base into two bits, which are packed together, resulting in a 44 byte exploit when translated.”



“Most of these bytes are used to encode an ASCII shell command,” he continued. “Four bytes are used to make the conversion function return to the system() function in the C standard library, which executes shell commands, and four more bytes were used to tell system() where the command is in memory.”



In other words: feed this strand of DNA into a compiler and it’s Hello World in 176 nucleobases. Three lines of math, indeed.

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