NEW YORK, January 17. /ITAR-TASS/. The malicious software that was used to steal personal data of 70 million customers of US-based retail chain Target was written “partly in Russian”, the online version of The Wall Street Journal reported on Thursday. The publication refers to a report made by federal and private investigators and sent to major retailers.

According to experts, this software dubbed KAPTOXA appeared on the hacking market in spring 2013. Apparently, comments to the program code were written in Russian.

The document notes that this hacking program was innovative and bespoke a high level of excellence of those who stood behind its creation. Antivirus software used in computing networks of American retail chains turned out to be useless in the face of it.

The report also contains recommendations for US-based retailers on how to resist this type of malicious software.

As earlier reported by Target (headquartered in Minneapolis, Minnesota), the hackers stole personal data of about 70 million customers that had made purchases during Christmas sales. The retailer immediately informed US authorities about the incident, and they initiated an investigation. It is not ruled out that other American retailers also became victims of this hacking attack.

Target is the third largest retail chain in the USA and has 1,900 shopping malls all over the country. According to experts, the occurred personal data leak became the second by its extent in the country;s history. In 2005-2006, cybercriminals accessed data of 94 million credit cards used by customers of another major American retailer TJX.