The worm, which cropped up last week, continued to infect systems across the world. Several Australian companies are among those to have their private documents emailed around the country.
"It's not quite a 'Love Bug,' but it's spreading very virulently," said Vincent Weafer, director of software maker Symantec's Antivirus Research Centre. Symantec rates the worm a four on its scale of one to five, with five being the most dangerous.
An added twist with SirCam is that the worm sends a random file from the infected computer's hard drive, potentially sending confidential business data or embarrassing personal information along with the virus. The subject line matches the name of the file being sent.
"That's a far more serious consequence for a person or business," Weafer said. "Once a document is gone from your organisation, it's gone."
Worm-infected messages received by this publication have included titles such as "Dear Diary," "expense distribution," "Wayne Gretzky" and "Pork with Leeks and Egg."
One factor limiting the likelihood that such files will actually be read is the fact that most network administrators set their email gateways to delete infected files. However, the settings can be changed to allow worms to be removed and the infected files opened.
Weafer said the company has received about 400 new reports of the worm from customers and those who use its Web site. That's about the same number that came in at the end of last week.
British email screening specialist MessageLabs reported seeing 7129 copies of the worm as of noon Monday British time.
"Although we have seen significant numbers of this virus in the US, we believe that Europe is still waiting to feel the brunt of the SirCam virus," MessageLabs CTO Mark Sunner said in a statement.
Although SirCam continues to spread, it appears to be getting caught before it can do much damage.
"We're seeing it bounce off the firewall," said David Perry, global director of education for antivirus software maker Trend Micro. "I am not seeing any reports of destructiveness."
So far, the worm still can be recognised because the text of the message contains one of three messages in either Spanish or English. They are "Hi! How are You?" "I send you this file in order to have your advice" and "See you later. Thanks."
MessageLabs said the English body text was present in 86 percent of the copies it received, with the remaining 14 percent bearing the Spanish translations.
Typically, variants crop up in which the body text of a worm is changed, but Weafer said so far he has only seen the single strain of SirCam.
"I would not be surprised if we did see variants," he said.
Want to know how to protect yourself against the SirCam worm? Or how to fix your PC if it has already been contaminated? Read this article.
