Entercom Communications Corp., the owner of KYW, WIP, WOGL, B101, and other Philadelphia stations, was hacked over the weekend, freezing its emails and causing computer systems to crash, according to published reports and sources.

The hackers — in what some call ransomware — have asked for $500,000, according to the reports.

Entercom, which owns 235 radio stations nationwide, did not respond to two emails on Wednesday.

“We are experiencing a disruption of some IT systems, including email,” the company told Chicago media blogger Robert Feder. “We apologize for any inconvenience and are working around the clock to resolve this issue.”

Among the systems affected were telephones, music scheduling, production, billing, and other internal digital systems, reports said. There also was concern whether the company could process the direct-deposit payroll on Friday.

Entercom is the nation’s second-largest radio station group, behind the iHeartRadio network. It has run into a slew of problems since it went deeply in debt to acquire the CBS Radio network in late 2017, which included the Philadelphia stations; its stock, which topped $16 a share in 2016, is down sharply over the last two years.

The online publication Radio Insight said that Entercom was the third national station group owner to be attacked with ransomware. The others were Townsquare Media and Radio One.

Radio Insight says that Entercom is not paying the ransom, and that the costs to fix the attack will go well beyond the $500,000. “In its first-quarter earnings report, Radio One indicated that it cost that amount for that company to repair issues connected to its attack in addition to $500,000 to $800,000 in lost advertising revenue,” the publication said.

Entercom is based in Bala Cynwyd but it has been widely reported that it plans to relocate its head offices and radio stations to an office building on the east side of the Schuylkill River, in the same location as the Aramark headquarters.

Entercom’s stock has had a bad run of late. Its shares cratered almost 40 percent on Aug. 6, when it announced its most recent results. A slowing second-quarter advertising market and weak ticket sales to Entercom events produced a 2.3% boost to revenues in the quarter, much lower than the 4% that Entercom CEO David Field had promised earlier this year.

Entercom went on to slash its dividend by 78% on Aug. 9. The new annual dividend is 8 cents a share, compared with 36 cents previously.

Investors seem to have lost patience with Entercom, which has repeatedly run into problems merging the two radio companies in a difficult business environment for legacy media platforms. At the time the deal was announced in early 2017, Entercom’s stock traded at $15 to $16 a share.

Its stock rose 10 cents on Wednesday, closing at $3.76. Its high year-to-date was $7.65 on Feb. 20.