Security vendor McAfee said there had been a sharp rise in the level of mobile phone malware in the firm's quarterly threat report.
The firm singled out Adobe and the PDF and Flash plug-ins as a popular target for malware authors, saying that Adobe had overtaken Microsoft as the target of cyber criminals.
"Throughout 2010 malware developers have heavily exploited weaknesses in both Flash and especially PDF technologies. McAfee Labs databases reveal that malicious PDFs targeting Adobe Acrobat topped the number of unique samples by a wide margin, making them the favorite target of client-side exploitation," said the report.
McAfee is in the process of being acquired by chipmaker Intel, a move which has already gained European regulatory approval.
"As we enter 2011, the momentum we have in our business serves as strong validation of our strategy and the confidence that our customers, partners and employees have in the proposed combination of McAfee and Intel," said McAfee boss Dave DeWalt in the firm's fourth quarter earnings release.
"We remain very comfortable with our ability as a wholely-owned subsidiary of Intel to effectively drive innovation in the security industry for years to come."