Client-side software that remains unpatched.
Waves of targeted email attacks, often called spear phishing, are exploiting client-side vulnerabilities in commonly used programs such as Adobe PDF Reader, QuickTime, Adobe Flash and Microsoft Office. This is currently the primary initial infection vector used to compromise computers that have Internet access. Those same client-side vulnerabilities are exploited by attackers when users visit infected web sites. (See Priority Two below for how they compromise the web sites). Because the visitors feel safe downloading documents from the trusted sites, they are easily fooled into opening documents and music and video that exploit client-side vulnerabilities. Some exploits do not even require the user to open documents. Simply accessing an infected website is all that is needed to compromise the client software. The victims' infected computers are then used to propagate the infection and compromise other internal computers and sensitive servers incorrectly thought to be protected from unauthorized access by external entities. In many cases, the ultimate goal of the attacker is to steal data from the target organizations and also to install back doors through which the attackers can return for further exploitation. On average, major organizations take at least twice as long to patch client-side vulnerabilities as they take to patch operating system vulnerabilities. In other words the highest priority risk is getting less attention than the lower priority risk.
Internet-facing web sites that are vulnerable.
Attacks against web applications constitute more than 60% of the total attack attempts observed on the Internet. These vulnerabilities are being exploited widely to convert trusted web sites into malicious websites serving content that contains client-side exploits. Web application vulnerabilities such as SQL injection and Cross-Site Scripting flaws in open-source as well as custom-built applications account for more than 80% of the vulnerabilities being discovered. Despite the enormous number of attacks and despite widespread publicity about these vulnerabilities, most web site owners fail to scan effectively for the common flaws and become unwitting tools used by criminals to infect the visitors that trusted those sites to provide a safe web experience.
Operating systems continue to have fewer remotely-exploitable vulnerabilities that lead to massive Internet worms.
Other than Conficker/Downadup, no new major worms for OSs were seen in the wild during the reporting period. Even so, the number of attacks against buffer overflow vulnerabilities in Windows tripled from May-June to July-August and constituted over 90% of attacks seen against the Windows operating system.
Rising numbers of zero-day vulnerabilities
World-wide there has been a significant increase over the past three years in the number of people discovering zero-day vulnerabilities, as measured by multiple independent teams discovering the same vulnerabilities at different times. Some vulnerabilities have remained unpatched for as long as two years. There is a corresponding shortage of highly skilled vulnerability researchers working for government and software vendors. So long as that shortage exists, the defenders will be at a significant disadvantage in protecting their systems against zero-day attacks. A large decline in the number of "PHP File Include" attacks appears to reflect improved processes used by application developers, system administrators, and other security professionals.
Web Application Attacks
There appear to be two main avenues for exploiting and compromising web servers: brute force password guessing attacks and web application attacks. Microsoft SQL, FTP, and SSH servers are popular targets for password guessing attacks because of the access that is gained if a valid username/password pair is identified. SQL Injection, Cross-site Scripting and PHP File Include attacks continue to be the three most popular techniques used for compromising web sites. Automated tools, designed to target custom web application vulnerabilities, make it easy to discover and infect several thousand web sites.
