EBay Inc posted a 13 percent rise in quarterly revenue on Wednesday, as better-than-expected results from its fast-growing PayPal division helped the online retailer overcome increasing competition from Amazon.com Inc and a well-publicized cyber attack. Ebay’s stock has fallen more than 8 percent since April, hurt by the cyber attack disclosed in May that compromised data for some 145 million customers, the departure of highly regarded PayPal chief David Marcus, and intensifying competition from both online and offline rivals.