Cybercriminals are establishing professional businesses and adopting corporate best practices, according to Symantec’s Internet Security Threat Report (ISTR).

This new class of professional cybercriminal spans the entire ecosystem of attackers, extending the reach of enterprise and consumer threats and fueling the growth of online crime, according to the security firm. 

“Advanced criminal attack groups now echo the skill sets of nation-state attackers. They have extensive resources and a highly-skilled technical staff that operate with such efficiency that they maintain normal business hours and even take the weekends and holidays off,” said Kevin Haley, director, Symantec Security Response. “We are even seeing low-level criminal attackers create call center operations to increase the impact of their scams."

Malware increased dramatically with 430 million new malware variants discovered in 2015, according to the report, which Symantec says proves that professional cybercriminals are leveraging their vast resources in attempt to overwhelm defenses and enter corporate networks.

Data breaches continue to impact the enterprise. In fact, large businesses that are targeted for attack will on average be targeted three more times this year. 2015 saw the largest data breach ever publicly reported with 191 million records compromised in a single incident. There were a record-setting total of nine reported mega-breaches. While 429 million identities were exposed, the number of companies that chose not to report the number of records lost jumped by 85 percent. A conservative estimate by Symantec of those unreported breaches pushes the real number of records lost to more than half a billion.

“The increasing number of companies choosing to hold back critical details after a breach is a disturbing trend,” said Haley. “Transparency is critical to security. By hiding the full impact of an attack, it becomes more difficult to assess the risk and improve your security posture to prevent future attacks.”

Ransomware also continued to evolve in 2015, with the more damaging style of crypto-ransomware attacks growing by 35 percent. This more aggressive kind of attack encrypts all of a victim’s digital content and holds it hostage until a ransom is paid. This year, ransomware spread beyond PCs to smartphones, Mac and Linux systems, with attackers increasingly seeking any network-connected device that could be held hostage for profit, indicating that the enterprise is the next target, according to the report.