Discover and read the best of Twitter Threads about #linux

Most recents (8)

#linux #bash #obfuscation #technique #bashfuscation
padding commands with history expansion characters (#exclamation mark (!))
! ! ! ! echo this is test
(removed the previous tweet as I revealed too much info !)
#linux #bash #obfuscation #bashfuscation

using history expansion character -> !! (i.e. last command)

ca
!!t really

is equivalent to
cat really

(only 4 interactive shell)
#linux #bash #obfuscation #bashfuscation

padding commands with empty commands (: ;)

: -> true (do nothing)
; -> command separator

: : ; : ; cat really
! ! ! : : ; : ; cat really
Read 8 tweets
Initially, #linuxgate won't have big effects on software quality. This is because most nerds are shitlibs, so there is a large pool of SJW-friendly programmers to draw from. /1
Maybe 10% to 15% of programmers are right-wing. You can run all of them out, and you can still have enough talented people to update glibc, git, curl, and all that. #linuxgate /2
Problems start to happen with the apolitical. Most people aren't political and resent having politics dragged into work. These are the people who foolishly think they can argue against a dumb policy or defend someone unjustly run out. #linuxgate /3
Read 9 tweets
Vai chegar ou já chegou na timeline de vocês uma discussão sobre os termos do novo Código de Conduta do #Linux. Aparentemente alguns desenvolvedores não gostaram do CdC e estão querendo cancelar suas contribuições ao kernel, supostamente ameaçando o Linux. Thread.
O Linux é gerenciado pela GPL2. A licença não menciona capacidade de cancelamento (revoke em inglês). Isso está mencionado como uma brecha que essas pessoas poderiam usar para cancelar o licenciamento do seu código. Na prática, isso é falso.
Essa thread do Stack Exchange dá as bases legais. Você pode ler pra se aprofundar.
opensource.stackexchange.com/a/4013/13174
Na prática somente se houvesse quebra dos termos da licença isso seria aplicável.
Read 13 tweets
Does AUSA Moira Kim Penza, prosecutor in the fed. #NXIVM #RICO criminal racketeering case, realize that her indictments of #NXIVM leader, Keith Raniere aka "Vanguard," last March, may have affected the outcome of the 2018 Mexican Presidential Election? #ArizonaMafia #Democrats
Moira Kim Penza is 1 of the main prosecutors in the federal #NXIVM #RICO criminal case. A #RICO case is very serious; it is 1 of the most complex types of prosecutions the U.S. Government can initiate. Moira's boss is Richard P. Donoghue, U.S. Atty for the Eastern District of NY.
Penza is a smart lawyer. According to publicly available information, she studied at Cornell Law School, a private Ivy League University located in Ithaca, New York. Cornell was ranked the #13 law school in America, out of 203 law schools, by U.S. News & World Report, in 2018.
Read 117 tweets
#linux #bash #path #obfuscation
goal: obfuscate /etc/passwd
1) #directorytraversal: /mnt/././../etc/././passwd
2) escape characher: /etc/.\/\/\/\/\/passwd /etc/.\/.\/.\/.\/passwd /\e\t\c/passwd
3) null character /et$'c/pa\u0000/notexist/path'sswd
....
#path #obfuscation using #symbolic #link
ln -s / anything
head -n 2 anything////../etc/passwd

ln -s ../../ wow
head -n 2 ././wow/../etc/passwd

* ../ after a sym link applies to the sym link not the current path
filename expansion #globbing

cat /et*/pa**wd

command expansion
$(echo /e)tc$(echo /pa*)wd

+ other string obfuscation techniques
Read 5 tweets
#linux #bash #obfuscation using shell parameter expansion:

alphabet=abcdefghijklmnopqrstuvwxyz
${alphabet:2:1}at really
${alphabet: -24:-23}at really
${alphabet: -24:1}at really
${alphabet:2:-23}at really

gnu.org/software/bash/…
similar #bat #windows (ss64.com/nt/syntax-subs…)
The goal is to obfuscate the following command:
cat really
in which, really is a file.
Using arithmetic (add, sub, mul, div, mod, and pow) for calculating index or lenght
${alphabet: 2:(-20-3)}at really
Read 6 tweets
#linux #bash #obfuscation using octal vals
$'\143\141\164' really

gnu.org/software/bash/…
"Words of the form $'string' are treated specially. The word expands to string, with backslash-escaped characters replaced as specified by the ANSI C standard."

Variations
$'\143'$'\141'$'\164' really
$'\143'''$'\141'''''''''''''$'\164' really
$'\143'''$'\141'''""''''""''$'\164' really

Explanation:
'' -> empty string
""-> empty string
'a''b' -> 'ab' (concatenation)

(deleted the previous one, as the picture had a problem)
To give you a headache

t=
$'\143'''$'\141'$t''"$t"''`$t`''$'\164' really
Read 13 tweets
Do-It-Yourself Keyboards. Added helix keyboard.
xahlee.info/kbd/diy_keyboa…
the classic Microsoft Natural Keyboard Elite (year 1998 to 2014) is now $199 on amazon.
amzn.to/2qKUVPn
see
Microsoft Natural Keyboard
xahlee.info/kbd/Microsoft_…
which do you prefer
Read 32 tweets

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