Yesterday, a zero-day exploit in the Adobe Reader and Adobe Acrobat software had been discovered and revealed to be extant in the wild. After being updated on this problem, Adobe released a public security advisory and announced that fixes were arriving soon.

Meanwhile, defense contractors and companies have caught phishing attempts circulating using maliciously coded e-mails containing infected PDF documents.

Researchers at Symantec say that they’ve caught the Trojan Sykipot using this zero-day exploit in the wild.

“This critical vulnerability has recently been seen exploited in the wild in targeted attack emails sent on November 1st and 5^th,” writes Stephen Doherty in the Symantec official blog. “This attack leverages the zero-day vulnerability in order to infect target computers with Backdoor.Sykipot.”

Targeted attacks using Backdoor.Sykipot have been seen in the wild since January, 2010 and this is not the first time it has been used in conjunction with zero-day exploits.

“We’ve seen [this targeting] people at telecommunications, manufacturing, computer hardware and chemical companies, as well as those in the defense sector,” said Joshua Talbot, senior security manager in Symantec’s security response group, in an interview Wednesday with Computerworld.

The researchers have said they’re continuing analysis of the exploit.