1. Symantec/
  2. Security Response/
  3. W32.HLLC.Happylow


Risk Level 1: Very Low

September 10, 2002
February 13, 2007 11:40:23 AM
Also Known As:
HLLC.HappyFlowers, W32.Walcomp
Systems Affected:

W32.HLLC.Happylow is a companion virus that encrypts all .exe files that reside in the same folder as the virus and renames them with a .wal extension. It then makes a copy of itself as the original file name.

For example, the virus encrypts the file Calc.exe and renames it to Calc.wal. Then the virus copies itself as Calc.exe, so that when the infected Calc.exe is executed, the virus executes its routine. Finally, it decrypts the Calc.wal file and executes it to make it appear that Calc.exe has run normally.

Antivirus Protection Dates

  • Initial Rapid Release version September 10, 2002
  • Latest Rapid Release version September 28, 2010 revision 054
  • Initial Daily Certified version September 10, 2002
  • Latest Daily Certified version September 28, 2010 revision 036
  • Initial Weekly Certified release date September 10, 2002
Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.
Writeup By: Gor Nazaryan

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