@Shaunak, Linux is not Windows!! Almost all the viruses that do damage to Windows O.S
won't work in Linux. Also there's no need for anti-spyware. Don't worry Linux is more secure.
Also the 'Avast Linux Home Edition' that you downloaded only works in cmd-line!!
For help with 'Avast' , open the Terminal Window & type:
$
avast --help
Usage: avast [OPTION...] <areaname...>
avast v1.0.6 -- command-line virus scanner
Options:
-_, --console Application will be working in STDIN/STDOUT mode
-a, --testall Test all of the files (default)
-b, --blockdevices Scan block devices
-c, --testfull Scan entire files
-d, --directory Scan only directory content
-i, --ignoretype Ignore virus sets
-n, --nostats No virus check statistics
-p, --continue=1234 Automatic action with infected file:
1:delete, 2
not supported), 3:repair, 4:stop
-r, --report=[*]file Create report file, '*' for OK results
-t, --archivetype[=ZGBTIJRXOQHFVPYD6UWAN] Scan archives: Z:ZIP(default),
G:GZ(default), B:BZIP2(default), T:TAR(default),
I:MIME, J:ARJ, R:RAR, X:Exec(default), O:ZOO,
Q:ARC, H:LHA, F:TNEF, V:CPIO, P:RPM, Y:ISO,
D
BX, 6:SIS, U:OLE, W:WINEXEC(default), A:All,
N:None
-v, --viruslist=mask Show list of all specific viruses
-h, --help Give this help list
--usage Give a short usage message
-V, --version Print program version
Mandatory or optional arguments to long options are also mandatory or optional
for any corresponding short options.
Report bugs to <support@avast.com>.