The Internet security threat landscape is changing, according to security firm Symantec. Attackers are moving away from large, multipurpose attacks on network perimeters and towards smaller, more focused attacks on client-side targets.
This most recent edition of the Symantec Internet Security Threat Report, released in September, notes that the new threat landscape will likely be dominated by emerging threats such as bot networks, customizable modular malicious code, and targeted attacks on Web applications and Web browsers. Whereas traditional attack activity has been motivated by curiosity and a desire t o show off technical virtuosity, many current threats are motivated by profit and a desire to perpetrate criminal acts, such as identity theft, extortion, and fraud.
In the previous Internet Security Threat Report, Symantec cautioned that malicious code for profit was on the rise. This concern appears to have been borne out. 64% of the top 50 malicious code samples reported to Symantec allowed spam relaying. The firm also detected a Trojan that downloads and installs adware that displays pop-up advertisements in the user’s Web browser. Additionally, bot networks and custom bot code are readily available for purchase or rent, confirming Symantec’s assertion that bot networks are increasingly being used for illicit financial gain. On average, during the last reporting period, Symantec observed 10,352 active bot network computers per day, an increase of over 100% from the previous reporting period. This is a serious security concern: it is reasonable to assume that as the financial rewards increase, attackers will develop more sophisticated and stealthier malicious code that will attempt to disable antivirus, firewalls, and other security measures.
As attackers have moved towards smaller, more modular malicious code (malicious code that downloads additional, more serious functionality) the number of variants threatens to overwhelm current defenses and increases the likelihood of a potentially critical compromise.