Newly discovered vulnerabilities in millions of fax machines and printers worldwide could allow criminals to hack networks by sending malicious faxes. This is according to new Check Point research, which reveals that cyber criminals are targeting company and private fax machines to take over networks and spread malware via the communication protocols. "A fax number is all an attacker needs to exploit the flaws, and potentially seize control of a company or home network. [A fax number is] is often publicly available on any employee's business card or company Web site," the report points out. Check Point researchers say they discovered the vulnerabilities in the popular HP Officejet Pro All-in-One fax printers, and shared the findings with HP. Following the discovery, the printer company has developed a software patch. The same protocols used in HP Officejet Pro All-in-One fax printers are used by many other vendors' fax machines and multifunction printers, and by online fax services such as fax2email, so it is likely these are also vulnerable to attacks by the same method, reveals the report.