Download.ject was the first noted case in which users of Internet Explorer for Windows could infect their computers with malware (a backdoor and key logger) merely by viewing a web page. It came to prominence during a widespread attack starting June 23, 2004. Infected servers included several financial sites. Security consultants prominently started promoting the use of Opera or Mozilla Firefox instead of IE in the wake of this attack.
Attack of June 23, 2004
Hackers placed Download.ject on financial and corporate websites running IIS 5.0 on Windows 2000, breaking in using a known vulnerability. (A patch existed for the vulnerability, but many administrators had not applied it.) The attack was first noticed June 23, although some researchers think it may have been in place as early as June 20.
Both the server  and browser  flaws had been exploited before this. This attack was notable, however, for combining the two, for having been placed upon popular mainstream websites (although a list of affected sites was not released) and for the network of compromised sites used in the attack reportedly numbering in the thousands, far more than any previous such compromised network.
This particular attack was neutralised on June 25 when the server from which Download.ject installed a backdoor was shut down. Microsoft issued a patch for Windows 2000, 2003 and XP on July 2.
Although not a sizable attack compared to email worms of the time, the fact that almost all existing installations of IE — 95% of web browsers in use at the time — were vulnerable, and that this was the latest in a series of IE holes leaving the underlying operating system vulnerable, caused a notable wave of concern in the press. Even some business press started advising users to switch to other browsers, despite the then-prerelease Windows XP SP2 being invulnerable to the attack.
- IIS 5 Web Server Compromises (CERT, 24 June 2004)
- Compromised Web Sites Infect Web Surfers (SANS Internet Storm Center, 25 June 2004)
- Berbew/Webber/Padodor Trojan Analysis (LURHQ Threat Intelligence Group, 25 June 2004) — analysis of the backdoor program installed on users' PCs
- What You Should Know About Download.Ject (Microsoft, 24 June 2004)
- Microsoft Statement Regarding Download.Ject Malicious Code Security Issue (Microsoft, 26 June 2004)
- Microsoft Security Bulletin MS04-011: Security Update for Microsoft Windows (835732) (Microsoft, 13 April 2004) — patch for server flaw
- MHTML URL Processing Vulnerability (Common Vulnerabilities and Exposures, 5 April 2004) — the IE flaw for which a patch was available at the time
- Internet Explorer Cross-Zone Vulnerability Exploitation (Internet Security Systems, 25 June 2004) — the IE flaw for which no patch was available at the time
- How to disable the ADODB.Stream object from Internet Explorer (Microsoft Knowledge Base article 870669) — the patch for the second IE flaw
- CFCU web site infects Ithaca customers' computers (Mark H. Anbinder, 14850 Today, 24 June 2004)
- Experts studying Internet attack (Associated Press, 24 June 2004)
- Researchers warn of infectious Web sites (Robert Lemos, ZDNet, 24 June 2004)
- Web site virus attack blunted (Robert Lemos, CNet, 25 June 2004)
- Internet Attack Slowing Down (George V. Hulme, Information Week, 25 June 2004)
- Virus Designed to Steal Windows Users' Data: Hundreds of Web Sites Targeted (Brian Krebs, Washington Post, 26 June 2004, page A01)
- IE flaw may boost rival browsers (Robert Lemos and Paul Festa, CNet, 28 June 2004)
- What's the New IE Flaw All About? (Stephen H. Wildstrom, Business Week, 29 June 2004)
- Internet Explorer Is Just Too Risky (Stephen H. Wildstrom, Business Week, 29 June 2004)
- Are the Browser Wars Back?: How Mozilla's Firefox trumps Internet Explorer (Paul Boutin, MSN Slate, 30 June 2004)
- Bruce Schneier: Microsoft still has work to do (Bill Brenner, SearchSecurity.com, 4 October 2004)