Executable installers are vulnerable^WEVIL (case 16): Trend Micro's installers allows arbitrary (remote) code execution Dec 31 2015 06:37AM
Stefan Kanthak (stefan kanthak nexgo de)
Hi @ll,

TrendMicro_MAX_10.0_US-en_Downloader.exe (available from
loads and executes ProfAPI.dll and UXTheme.dll (and other DLLs
too) eventually found in the directory it is started from
(the "application directory").

For software downloaded with a web browser the application
directory is typically the user's "Downloads" directory: see
and <http://seclists.org/fulldisclosure/2012/Aug/134>

If one of the DLLs named above gets planted in the user's
"Downloads" directory per "drive-by download" or "social
engineering" this vulnerability becomes a remote code execution.

Proof of concept/demonstration:

1. visit <http://home.arcor.de/skanthak/sentinel.html>, download
<http://home.arcor.de/skanthak/download/SENTINEL.DLL>, save it
as UXTheme.dll in your "Downloads" directory, then copy it as

2. download TrendMicro_MAX_10.0_US-en_Downloader.exe and save it
in your "Downloads" directory;

3. execute TrendMicro_MAX_10.0_US-en_Downloader.exe from your
"Downloads" directory;

4. notice the message boxes displayed from the DLLs placed in step 1.


For a denial of service instead of arbitrary (remote) code execution
copy the downloaded UXTheme.dll as OLEAcc.dll and WinSpool.drv.
This is easily turned into arbitrary (remote) code execution too:
just add the exports OpenPrinterW, ClosePrinter and DocumentPropertiesW
respectively LresultFromObject and CreateStdAccessibleObject to the DLL.

See <http://seclists.org/fulldisclosure/2015/Nov/101> and
<http://seclists.org/fulldisclosure/2015/Dec/86> as well as
<http://home.arcor.de/skanthak/sentinel.html> and the still unfinished
<http://home.arcor.de/skanthak/!execute.html> for more details about
this well-known and well-documented BEGINNER'S error and why
executable installers (and self-extractors too) are bad.

Additionally, TrendMicro_MAX_10.0_US-en_Downloader.exe creates an
unsafe temporary directory where it unpacks its payload to and
executes it from.

...\TrendMicro_MAX_10.0_US-en_Downloader\Agent\TisEzIns.exe loads
and executes multiple DLLs too from its unsafe application directory:
ProfAPI.dll, NTMarta.dll, RASAdHlp.dll, NTShrUI.dll, UXTheme.dll and
Secur32.dll plus WinMM.dll, Version.dll, WinSpool.drv, WinHttp.dll
and OLEAcc.dll

Proof of concept/demonstration:

5. unpack TrendMicro_MAX_10.0_US-en_Downloader.exe (basically a
7-Zip self-extractor) into an arbitrary directory, say "%TEMP%"
(this creates a subdirectory "%TEMP%\Agent" with the payload);

6. copy the downloaded UXTheme.dll from step 1 into "%TEMP%\Agent",
then copy it as ProfAPI.dll, NTMarta.dll, RASAdHlp.dll, NTShrUI.dll,
Secur32.dll plus WinMM.dll, Version.dll, WinSpool.drv, WinHttp.dll
and OLEAcc.dll there;

7. execute "%TEMP%\Agent\TisEZIns.exe";

8. notice the message boxes displayed from the DLLs placed in steps 5
and 6.


stay tuned
Stefan Kanthak


2015-12-20 multiple reports sent to vendor

2015-12-20 one report bounced due to braindead mail setup by vendor

2015-12-20 resent bounced report via alternative provider

2015-12-21 vendor acknowledges receipt and names further contact

2015-12-28 vendor verifies reports, can reproduce it on Windows 7

2015-12-30 vendor asks for verification:
"We did not reproduce the vulnerability relating to
ProfAPI.dll and UXTheme.dll on Windows 7."

2015-12-31 sent verification to vendor

2015-12-31 bounced due to braindead mail setup by vendor

<GCC_CONSRECEIVE (at) support.trendmicro (dot) com [email concealed]>: host
said: 554 5.7.1 <GCC_CONSRECEIVE (at) support.trendmicro (dot) com [email concealed]>: Recipient address
rejected: ERS-RBL. (in reply to RCPT TO command)

<tm-csirt (at) trendmicro (dot) com [email concealed]>: host sjdc-itpf-04.udc.trendmicro.com[]
said: 550 5.7.1 Service unavailable; Client host [] blocked
using Trend Micro RBL+. Please see
http://www.mail-abuse.com/cgi-bin/lookup?ip_address=; Mail
from blocked using Trend Micro Email Reputation database.
Please see <http://www.mail-abuse.com/cgi-bin/lookup?>;
from=<<stefan.kanthak (at) nexgo (dot) de [email concealed]> ; SIZE=8184> to=<<tm-csirt (at) trendmicro (dot) com [email concealed]>
; ORCPT=rfc822;tm-csirt (at) trendmicro (dot) com [email concealed]> proto=ESMTP
helo=<mail-in-03.arcor-online.net> (in reply to end of DATA command)

2015-12-31 report published: vendor is obviously not interested in

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