Re: Analysis on who is Jia Tan, and who he could work for, reading xz.git

[Alejandro Colomar <alx () kernel org>]

On Wed, Apr 10, 2024 at 05:16:52AM +0200, Alejandro Colomar wrote:
> Hi!
>
> Regarding <https://tukaani.org/xz-backdoor/>
>
> I've been researching xz.git to learn about this malicious actor, and
> who he might have worked for.
>
> This Jia Tan seems to work mostly with the +0800 timezone:
>
>       $ git log --all --author 'Jia Tan' \
>       | grep ^Date \
>       | grep -o '[+-][0-9][0-9][0-9]0' \
>       | sort \
>       | uniq -c;
>             4 +0200
>            10 +0300
>           676 +0800
>
> According to <https://www.timeanddate.com/time/map/>, in the summer,
> +0800 corresponds to China, or Taiwan, or Hong Kong, or Irkutsk (Russia),
> or Philippines or other small countries around it.  None of the regions
> in +0800 use DST.

For completeness, the list of tz database time zones that have +0800,
according to
<https://en.wikipedia.org/wiki/List_of_tz_database_time_zones>, are:

AQ      Antarctica/Casey
BN      Asia/Brunei
MN      Asia/Choibalsan
CN      Asia/Chongqing
CN      Asia/Chungking
CN      Asia/Harbin
HK      Asia/Hong_Kong
RU      Asia/Irkutsk
MY      Asia/Kuala_Lumpur
MY, BN  Asia/Kuching
MO      Asia/Macao
MO      Asia/Macau
ID      Asia/Makassar
PH      Asia/Manila
CN      Asia/Shanghai
SG, MY  Asia/Singapore
TW      Asia/Taipei
ID      Asia/Ujung_Pandang
MN      Asia/Ulaanbaatar
MN      Asia/Ulan_Bator
AU      Australia/Perth
AU      Australia/West
HK      Hongkong
CN      PRC
TW      ROC
SG      Singapore

> +0300 corresponds to, among others, Israel and Moscow, and then a bunch

And the time zones that have +0300 in the summer and +0200 in the
winter are:

EG      Africa/Cairo
LB      Asia/Beirut
CY      Asia/Famagusta
PS      Asia/Gaza
PS      Asia/Hebron
IL      Asia/Jerusalem
CY      Asia/Nicosia
IL      Asia/Tel_Aviv
EG      Egypt
GR      Europe/Athens
RO      Europe/Bucharest
MD      Europe/Chisinau
FI, AX  Europe/Helsinki
UA      Europe/Kiev
UA      Europe/Kyiv
AX      Europe/Mariehamn
CY      Europe/Nicosia
LV      Europe/Riga
BG      Europe/Sofia
EE      Europe/Tallinn
MD      Europe/Tiraspol
UA      Europe/Uzhgorod
LT      Europe/Vilnius
UA      Europe/Zaporozhye
IL      Israel

-- 
<https://www.alejandro-colomar.es/>

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