Gen.Variant.Symmi.8834_d78e936899

Dynamic Analysis

Payload

Behaviour	Description
WormAutorun	A worm can spread via removable drives. It writes its executable and creates "autorun.inf" scripts on all removable drives. The autorun script will execute the Backdoor's file once a user opens a drive's folder in Windows Explorer.

Process activity

The Backdoor creates the following process(es):

Cryptado.exe:1240
Cryptado.exe:2028
Cryptado.exe:1480
Cryptado.exe:1300
%original file name%.exe:1648

The Backdoor injects its code into the following process(es):

notepad.exe:1072
svchost.exe:1496

Mutexes

The following mutexes were created/opened:No objects were found.

File activity

The process %original file name%.exe:1648 makes changes in the file system.

The Backdoor creates and/or writes to the following file(s):

%Documents and Settings%\%current user%\Local Settings\Temp\IXP000.TMP\Cryptado.exe (2784 bytes)

The Backdoor deletes the following file(s):

%Documents and Settings%\%current user%\Local Settings\Temp\IXP000.TMP\Cryptado.exe (0 bytes)

The process notepad.exe:1072 makes changes in the file system.

The Backdoor creates and/or writes to the following file(s):

%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\desktop.ini (67 bytes)
%Documents and Settings%\%current user%\Application Data\Microsoft\Windows\i2kdM89PH2Sj.dat (322 bytes)
%System%\System32\svshost.exe (673 bytes)

Registry activity

The process Cryptado.exe:1240 makes changes in the system registry.

The Backdoor creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "D9 57 D6 71 85 4B 6D 7C 4A 64 6F F7 58 D8 50 93"

The Backdoor deletes the following registry key(s):

[HKCU\Software\Microsoft\MediaPlayer\Health\{A02EC1FC-CFFC-46EB-AF31-88DC9409840C}]

The process Cryptado.exe:2028 makes changes in the system registry.

The Backdoor creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "BB 4E B3 AA 25 E7 C3 6B 8F 3F 62 13 B8 63 0F FF"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd73-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd72-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{b98117e8-75ca-11e2-81b2-000c293708fb}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"AppData" = "%Documents and Settings%\%current user%\Application Data"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd75-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\XtremeRAT]
"Mutex" = "i2kdM89PH2Sj"

The Backdoor deletes the following registry key(s):

[HKCU\Software\XtremeRAT]

The process Cryptado.exe:1480 makes changes in the system registry.

The Backdoor creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "03 78 29 21 0A 3B 81 09 0F 08 A9 4B CD B7 97 8D"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd73-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd72-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{b98117e8-75ca-11e2-81b2-000c293708fb}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"AppData" = "%Documents and Settings%\%current user%\Application Data"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd75-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\XtremeRAT]
"Mutex" = "i2kdM89PH2Sj"

The process Cryptado.exe:1300 makes changes in the system registry.

The Backdoor creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "A8 9E 2C 89 3C 83 34 FF 47 24 E9 3A F3 9A 30 C3"

The Backdoor deletes the following registry key(s):

[HKCU\Software\Microsoft\MediaPlayer\Health\{F06B3D8D-9E9C-427D-99AB-AAC0C9A370A3}]

The process %original file name%.exe:1648 makes changes in the system registry.

The Backdoor creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "69 C3 1C 86 B8 3D 50 C3 E3 AB BE 00 F8 2E 42 16"

To automatically run itself each time Windows is booted, the Backdoor adds the following link to its file to the system registry autorun key:

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce]
"wextract_cleanup0" = "rundll32.exe %System%\advpack.dll,DelNodeRunDLL32 C:\DOCUME~1\"%CurrentUserName%"\LOCALS~1\Temp\IXP000.TMP\"

The Backdoor deletes the following value(s) in system registry:

The Backdoor disables automatic startup of the application by deleting the following autorun value:

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce]
"wextract_cleanup0"

The process notepad.exe:1072 makes changes in the system registry.

The Backdoor creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Active Setup\Installed Components\{TVJ3D5PS-H16L-W7SR-V351-0716AO2D1WQA}]
"StubPath" = "%System%\System32\svshost.exe restart"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths]
"Directory" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path4]
"CacheLimit" = "65452"
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache4"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Connections]
"SavedLegacySettings" = "3C 00 00 00 1E 00 00 00 01 00 00 00 00 00 00 00"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"AppData" = "%Documents and Settings%\%current user%\Application Data"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd73-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path3]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache3"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Cookies" = "%Documents and Settings%\%current user%\Cookies"

[HKLM\SOFTWARE\Microsoft\DirectDraw\MostRecentApplication]
"ID" = "1208111751"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path2]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache2"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Common AppData" = "%Documents and Settings%\All Users\Application Data"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd75-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Cache" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files"

[HKLM\SOFTWARE\Microsoft\DirectDraw\MostRecentApplication]
"Name" = "notepad.exe"

[HKLM\System\CurrentControlSet\Hardware Profiles\0001\Software\Microsoft\windows\CurrentVersion\Internet Settings]
"ProxyEnable" = "0"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path1]
"CacheLimit" = "65452"

[HKCU\Software\i2kdM89PH2Sj]
"ServerStarted" = "22/07/2016 20:39:53"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path2]
"CacheLimit" = "65452"

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "2D 32 AD 55 FA 15 7D 84 93 F0 FE 73 2D 20 46 9F"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path1]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache1"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path3]
"CacheLimit" = "65452"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"MigrateProxy" = "1"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd72-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{b98117e8-75ca-11e2-81b2-000c293708fb}]
"BaseClass" = "Drive"

[HKCU\Software\i2kdM89PH2Sj]
"ServerName" = "%System%\System32\svshost.exe"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths]
"Paths" = "4"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"History" = "%Documents and Settings%\%current user%\Local Settings\History"

To automatically run itself each time Windows is booted, the Backdoor adds the following link to its file to the system registry autorun key:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
"Win32" = "%System%\System32\svshost.exe"

The Backdoor modifies IE settings for security zones to map all local web-nodes with no dots which do not refer to any zone to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"UNCAsIntranet" = "1"

To automatically run itself each time Windows is booted, the Backdoor adds the following link to its file to the system registry autorun key:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
"SkypeUpdate" = "%System%\System32\svshost.exe"

Proxy settings are disabled:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"ProxyEnable" = "0"

The Backdoor modifies IE settings for security zones to map all urls to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"IntranetName" = "1"

The Backdoor modifies IE settings for security zones to map all web-nodes that bypassing the proxy to the Intranet Zone:

"ProxyBypass" = "1"

To automatically run itself each time Windows is booted, the Backdoor adds the following link to its file to the system registry autorun key:

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
"Win32" = "%System%\System32\svshost.exe"

The Backdoor deletes the following value(s) in system registry:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"AutoConfigURL"
"ProxyServer"
"ProxyOverride"

Dropped PE files

MD5	File path
cfa70b465a9aae502cee79815d2fa8f6	c:\Documents and Settings\"%CurrentUserName%"\Local Settings\Temp\IXP000.TMP\Cryptado.exe
cfa70b465a9aae502cee79815d2fa8f6	c:\WINDOWS\system32\System32\svshost.exe

HOSTS file anomalies

No changes have been detected.

Rootkit activity

No anomalies have been detected.

Propagation

A worm can spread via removable drives. It writes its executable and creates "autorun.inf" scripts on all removable drives. The autorun script will execute the Backdoor's file once a user opens a drive's folder in Windows Explorer.

Removals

Remove it with Ad-Aware

1. Click (here) to download and install Ad-Aware Free Antivirus.
2. Update the definition files.
3. Run a full scan of your computer.

Manual removal*

1. Terminate malicious process(es) (How to End a Process With the Task Manager):

   Cryptado.exe:1240
   Cryptado.exe:2028
   Cryptado.exe:1480
   Cryptado.exe:1300
   %original file name%.exe:1648
   

2. Delete the original Backdoor file.
   
3. Delete or disinfect the following files created/modified by the Backdoor:

   %Documents and Settings%\%current user%\Local Settings\Temp\IXP000.TMP\Cryptado.exe (2784 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\desktop.ini (67 bytes)
   %Documents and Settings%\%current user%\Application Data\Microsoft\Windows\i2kdM89PH2Sj.dat (322 bytes)
   %System%\System32\svshost.exe (673 bytes)

4. Delete the following value(s) in the autorun key (How to Work with System Registry):

   [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce]
   "wextract_cleanup0" = "rundll32.exe %System%\advpack.dll,DelNodeRunDLL32 C:\DOCUME~1\"%CurrentUserName%"\LOCALS~1\Temp\IXP000.TMP\"
   
   [HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
   "Win32" = "%System%\System32\svshost.exe"
   
   [HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
   "SkypeUpdate" = "%System%\System32\svshost.exe"
   
   [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
   "Win32" = "%System%\System32\svshost.exe"

5. Find and delete all copies of the worm's file together with "autorun.inf" scripts on removable drives.
   
6. Reboot the computer.
   

*Manual removal may cause unexpected system behaviour and should be performed at your own risk.

Static Analysis

VersionInfo

Company Name: Microsoft Corporation
Product Name: HD Player
Product Version: 6.00.2900.5512
Legal Copyright: (c) Microsoft Corporation. Todos os direitos reservados.
Legal Trademarks:
Original Filename: WEXTRACT.EXE
Internal Name: Wextract
File Version: 6.00.2900.5512 (xpsp.080413-2105)
File Description: Auto-extrator de arquivo de gabinete Win32
Comments:
Language: English (United States)

Company Name: Microsoft CorporationProduct Name: HD Player Product Version: 6.00.2900.5512Legal Copyright: (c) Microsoft Corporation. Todos os direitos reservados.Legal Trademarks: Original Filename: WEXTRACT.EXE Internal Name: Wextract File Version: 6.00.2900.5512 (xpsp.080413-2105)File Description: Auto-extrator de arquivo de gabinete Win32 Comments: Language: English (United States)

PE Sections

Name	Virtual Address	Virtual Size	Raw Size	Entropy	Section MD5
.text	4096	39368	39424	4.5602	2de9bfc784c63236572bd70efc20545d
.data	45056	7140	1024	2.94449	99858e86526942a66950c7139f78a725
.rsrc	53248	142860	143360	5.3206	6bddb8a80e95d378e2da964eb3dbfe3b

Dropped from:

Downloaded by:

Similar by SSDeep:

Similar by Lavasoft Polymorphic Checker:

Network Activity

URLs

IDS verdicts (Suricata alerts: Emerging Threats ET ruleset)

Traffic

Map

The Backdoor connects to the servers at the folowing location(s):

Strings from Dumps

svchost.exe_1496:

.text

.text

`.data

`.data

.rsrc

.rsrc

ADVAPI32.dll

ADVAPI32.dll

KERNEL32.dll

KERNEL32.dll

NTDLL.DLL

NTDLL.DLL

RPCRT4.dll

RPCRT4.dll

NETAPI32.dll

NETAPI32.dll

ole32.dll

ole32.dll

ntdll.dll

ntdll.dll

RegCloseKey

RegCloseKey

RegOpenKeyExW

RegOpenKeyExW

GetProcessHeap

GetProcessHeap

NtOpenKey

NtOpenKey

svchost.pdb

svchost.pdb

\PIPE\

\PIPE\

Software\Microsoft\Windows NT\CurrentVersion\Svchost

Software\Microsoft\Windows NT\CurrentVersion\Svchost

\Registry\Machine\System\CurrentControlSet\Control\SecurePipeServers\

\Registry\Machine\System\CurrentControlSet\Control\SecurePipeServers\

5.1.2600.5512 (xpsp.080413-2111)

5.1.2600.5512 (xpsp.080413-2111)

svchost.exe

svchost.exe

Windows

Windows

Operating System

Operating System

5.1.2600.5512

5.1.2600.5512

svchost.exe_1496_rwx_10000000_0004D000:

`.rsrc

`.rsrc

ServerKeyloggerU

ServerKeyloggerU