You really didn't include enough information (for example, the NAME of the files that avast detected). "Malware - gen" might indicate a virus --- then again, it may simply be a "false positive" detection... especially if, as you asserted, "it's only an Avast issue".   (Which again stresses the need for you to procede carefully, getting proper analysis of YOUR particular situation.) I believe I located the avast forum thread you're referring to.   One of the tools suggested there was ComboFix.   Be advised that ComboFix should NOT be run unless you are personally advised to do so, under the supervision of a malware removal expert. Unfortunately, one-on-one Malware Analysis/Removal is no longer done at the Dell Forums.    
I use the free version of Avast in addition to Malwarebytes that I use on my Inspiron 14R - Windows 7.  This afternoon Avast started with pop-up warnings saying: Trojan Horse Blocked.  Infection:  Win 32 Downloader PKU [Trg] and  Infection:  Win 32 Malware - gen Action:  Moved to chest. I ran Spybot and Malwarebytes.  They found and cleaned up some stuff but the pop ups keep coming.   These warnings are popping up every 5 minutes or so.  I Googled  "Win 32 Downloader PKU [Trg] " and the only reliable site talking about the malware is a an Avast forum which recommends posting a long report, disabling Avast, downloading and running other software programs and so on.  The forum posts on the issue are very recent but what they are suggesting seems a a bit too complicated for me.   Is this a serious issue and is there a an easier way to deal with  it.  I don't understand why it's only an Avast issue.  Can I do a restore or should I buy or use  some other anti virus software?   Any advice would be appreciated.      
Win32 Downloader PKU [TRG] Virus or Malware