NEW YORK (Reuters) - Super Micro Computer Inc shares fell 16 percent on Tuesday after Bloomberg News reported that a major U.S. telecommunications firm had uncovered a malicious implant on a Super Micro server.
The report follows a Bloomberg Businessweek article last Thursday that Super Micro systems had been infiltrated by malicious computer chips inserted by Chinese intelligence agents, sending its shares down 38 percent.
Super Micro, a maker of computer servers, denied the claims in both articles.
Super Micro shares were down $2.31 to $12.44 in midafternoon Pink Sheet trade.
On Tuesday, Bloomberg cited security consultant Yossi Appleboum as saying that he found the malicious hardware in August while inspecting unusual communications from a server at the telecommunications firm. The story did not identify the telecom company.
Super Micro said on Tuesday that it did not know of any cases like the one described by Bloomberg.
“We have seen no evidence of any unauthorized components in our products, no government agency has informed us that they have found unauthorized components on our boards, and no customer has reported finding any such unauthorized components,” the statement said.
Security experts and U.S. and UK authorities said they had no knowledge of the attacks described in last Thursday’s article, which cited 17 unnamed sources. They also expressed surprise at the discrepancy between the claims in the Bloomberg Businessweek article and the strongly worded denials by Super Micro and other companies named in the piece.
Representatives with AT&T Inc and Sprint Corp said on Tuesday that they did not use Super Micro servers. T-Mobile US Inc and Verizon Communications Inc said they were not affected by an attack like the one described by Bloomberg.
Appleboum, who is chief executive of cyber-security firm Sepio Systems, told Reuters that he had uncovered malicious hardware on Super Micro servers at more than one U.S. telecommunications firm.
He declined to identify the telecom companies or say how the malicious hardware had been inserted on the servers.
(This version of the story corrects to Bloomberg Businessweek in paragraphs 2 and 8)
Reporting by Jim Finkle and Sheila Dang in New York; Editing by Susan Thomas