On January 24, 2005, an intruder update of exchange software resulted in customer text messages not being sent. Vodafone Greece sent firmware dumps of the affected exchanges to Ericsson for analysis. On March 4, 2005, Ericsson located the rogue code, 6500 lines of code written in the PLEX programming language used by Ericsson AXE switches. Writing such sophisticated code in a very esoteric language required a high level of expertise. Much of Ericsson's software development for AXE had been done by an Athens-based company named Intracom Telecom, so the skills needed to write the rogue software were likely available within Greece.