clydeiii/cybersecurity · Datasets at Hugging Face

text stringlengths 4 429
Value: ServiceDLL Data: %temp%\c_1758.nls
Potential variation
PAYLOAD
The payload uses two-stage installation. During stage one, the dropper will install
GLANCE UNDER THE HOOD
the payload as a service running under the name Ups??? (where ??? are three
buffer after phase one XOR:
random characters). Once executing, the payload will immediately delete the first
mJ2bhcPExs7excLThcjExqurnauYq
service and enter stage-two. During stage-two, the payload will register a new,
buffer after base64 decoding:
second service under the name RaS??? (where ??? are three random characters).
This new service will point to the same backdoor DLL, no new files are involved.
Note: the three character prefixes Ups and RaS can easily be modified by the attacker.
Once the new service is registered, the payload will access an embedded resource
that is encrypted. The decryption goes through several phases. The encrypted data block contains the DNS name for
the command and control server (homeunix.com, etc). This data block is configurable before the malware is
deployed. The data block length is hard-coded (0x150 or 336 bytes). During phase one, this data block is fed through a
simple XOR (0x99), resulting in an ASCII-string. Next, the resulting ASCII-string is fed into a base64 decoding
function, producing a binary string. Finally, the resulting base64 decoded binary string is fed through another XOR
(0xAB), resulting in clear-text. The three primary encryption loops are colored and marked in Figure 1. The resulting
clear-text buffer contains several fields in both ASCII and UNICODE, including the C&C server address.
Actionable Intelligence
Pattern
C&C Server DNS
.homeunix.com (where is any subdomain)
*.homelinux.com
*.ourhobby.com
*.3322.org
*.2288.org
*.8866.org
*.ath.cx
*.33iqst.com
*.dyndns.org
*.linode.com
*.ftpaccess.cc
*.filoups.info
*.blogsite.org
The payload will create additional registry keys.
Actionable Intelligence
Pattern
Additional Key
HKLM\Software\Sun\1.1.2\IsoTp
Additional Key
HKLM\Software\Sun\1.1.2\AppleTlk
Other potential dropped files, as reported by McAfee:
Actionable Intelligence
Pattern
Additional File
securmon.dll
Additional File
AppMgmt.dll
Additional File
A0029670.dll (A00#####.dll)
Additional File
msconfig32.sys
Additional File
VedioDriver.dll
Additional File
acelpvc.dll
Additional File
wuauclt.exe
Additional File
jucheck.exe
Additional File
AdobeUpdateManager.exe
Additional File
zf32.dll
COM M AND AND CONTRO L
The payload communicates with its command and control server over port 443. The source port is randomly selected.
While outbound traffic appears to be HTTPS, the actual traffic uses a weak custom encryption scheme. The command
and control packets have a very specific formativ.
command
parameters
0x00000001
payload len
payload
The payload section is encrypted with a key selected by using GetTickCount. This means each infected node has its
own key. The key is embedded in the header of the packet, and is easily recovered.
D IAGNOSE
HOW THE MALWARE WORKS
The primary control logic can be found in the module registered under the service key (rasmon.dll, etc.). This module has
been written in c and includes several specific methods and encodings that provide
forensic track-ability.
The above screenshot illustrates a REcon(tm) trace on the malware dropper and
subsequent service creation. Location A. represents the dropper program, which unpacks
itself and decompresses a file to the system32 directory. Point B. represents the initial
svchost.exe startup, which is loading the malware payload. Location C. is the actual
execution of the malware service, which remains persistent. At points E. and F. you can
see the malware checking in with the command and control server. Finally, location D.
represents the dissolvable batch file which deletes the initial dropper and then itself.
F IGURE 1 - BASE 64 AND XOR
ENCRYPTION SCHEME
CAPABILITY
The malware has generic and flexible capabilities. There are distinct command
handlers in the malware that allow files to be stolen and remote commands to
be executed. The command handler is illustrated in Figure 2. At location A. the
command number is checked. At locations marked B. are each individual
command handler, as controlled by the C&C server and command number in
the C&C packet. Location C. is where the result of each command is sent back

Value: ServiceDLL Data: %temp%\c_1758.nls

Potential variation

PAYLOAD

The payload uses two-stage installation. During stage one, the dropper will install

GLANCE UNDER THE HOOD

the payload as a service running under the name Ups??? (where ??? are three

buffer after phase one XOR:

random characters). Once executing, the payload will immediately delete the first

mJ2bhcPExs7excLThcjExqurnauYq

service and enter stage-two. During stage-two, the payload will register a new,

buffer after base64 decoding:

second service under the name RaS??? (where ??? are three random characters).

This new service will point to the same backdoor DLL, no new files are involved.

Note: the three character prefixes Ups and RaS can easily be modified by the attacker.

Once the new service is registered, the payload will access an embedded resource

that is encrypted. The decryption goes through several phases. The encrypted data block contains the DNS name for

the command and control server (homeunix.com, etc). This data block is configurable before the malware is

deployed. The data block length is hard-coded (0x150 or 336 bytes). During phase one, this data block is fed through a

simple XOR (0x99), resulting in an ASCII-string. Next, the resulting ASCII-string is fed into a base64 decoding

function, producing a binary string. Finally, the resulting base64 decoded binary string is fed through another XOR

(0xAB), resulting in clear-text. The three primary encryption loops are colored and marked in Figure 1. The resulting

clear-text buffer contains several fields in both ASCII and UNICODE, including the C&C server address.

Actionable Intelligence

Pattern

C&C Server DNS

*.homeunix.com (where * is any subdomain)

*.homelinux.com

*.ourhobby.com

*.3322.org

*.2288.org

*.8866.org

*.ath.cx

*.33iqst.com

*.dyndns.org

*.linode.com

*.ftpaccess.cc

*.filoups.info

*.blogsite.org

The payload will create additional registry keys.

Actionable Intelligence

Pattern

Additional Key

HKLM\Software\Sun\1.1.2\IsoTp

Additional Key

HKLM\Software\Sun\1.1.2\AppleTlk

Other potential dropped files, as reported by McAfee:

Actionable Intelligence

Pattern

Additional File

securmon.dll

Additional File

AppMgmt.dll

Additional File

A0029670.dll (A00#####.dll)

Additional File

msconfig32.sys

Additional File

VedioDriver.dll

Additional File

acelpvc.dll

Additional File

wuauclt.exe

Additional File

jucheck.exe

Additional File

AdobeUpdateManager.exe

Additional File

zf32.dll

COM M AND AND CONTRO L

The payload communicates with its command and control server over port 443. The source port is randomly selected.

While outbound traffic appears to be HTTPS, the actual traffic uses a weak custom encryption scheme. The command

and control packets have a very specific formativ.

command

parameters

0x00000001

payload len

payload

The payload section is encrypted with a key selected by using GetTickCount. This means each infected node has its

own key. The key is embedded in the header of the packet, and is easily recovered.

D IAGNOSE

HOW THE MALWARE WORKS

The primary control logic can be found in the module registered under the service key (rasmon.dll, etc.). This module has

been written in c and includes several specific methods and encodings that provide

forensic track-ability.

The above screenshot illustrates a REcon(tm) trace on the malware dropper and

subsequent service creation. Location A. represents the dropper program, which unpacks

itself and decompresses a file to the system32 directory. Point B. represents the initial

svchost.exe startup, which is loading the malware payload. Location C. is the actual

execution of the malware service, which remains persistent. At points E. and F. you can

see the malware checking in with the command and control server. Finally, location D.

represents the dissolvable batch file which deletes the initial dropper and then itself.

F IGURE 1 - BASE 64 AND XOR

ENCRYPTION SCHEME

CAPABILITY

The malware has generic and flexible capabilities. There are distinct command

handlers in the malware that allow files to be stolen and remote commands to

be executed. The command handler is illustrated in Figure 2. At location A. the

command number is checked. At locations marked B. are each individual

command handler, as controlled by the C&C server and command number in

the C&C packet. Location C. is where the result of each command is sent back