1679589000
在 Debian 中禁用 APT 缓存
在 Debian 系统中，软件包通常是通过 apt 软件包管理器安装的，它从官方的 Debian 存储库安装软件包。通过 apt 安装的包被移动到缓存目录并在位置'/var/cache/apt/archives'内进行管理。之所以将这些文件放在缓存目录中，是为了保证下次安装一个已经存在的包的依赖包时，不会再安装同一个包；相反，它将从该位置提取包裹。随着时间的流逝，软件包失去了它的价值，总有一天它不再需要系统了。因此，最好在 Debian 系统上禁用 apt 缓存，因为这将有助于释放一些空间。
按照本文的详细指南在 Debian 中禁用apt 缓存。
如何在 Debian 中禁用 APT 缓存
下面给出了在 Debian 中禁用apt 缓存的简单分步说明：
第一步：首先，你必须通过nano编辑器在Debian系统上创建一个00clean-cache-dir文件：
sudo nano /etc/apt/apt.conf.d/00clean-cache-dir第 2 步：在文件中，您必须添加以下行：
DPkg::Post-Invoke {"/bin/rm -f /var/cache/apt/archives/*.deb || true";};
第三步：然后用“CTRL+X”保存干净的缓存文件，加“Y”回车退出。
第 4 步：然后您必须创建另一个名称为“00disbale-cache-files”的文件：
sudo nano 00disable-cache-files第 5 步：在此文件中，添加以下行：
Dir::Cache::srcpkgcache "";
Dir::Cache::pkgcache "";
第 6 步：使用第 3 步保存此文件。
这将禁用Debian 系统上的apt 缓存。
第 7 步：现在 apt 缓存已被禁用，最好使用以下命令清空 Debian 上的“/var/cache/apt/archives”目录：
sudo rm -rf /var/cache/apt/archives
第 8 步（可选）：或者，运行以下命令删除缓存是一个很好的做法：
sudo apt clean --dry-run
第 9 步（可选）：此外，您还可以通过以下命令删除缓存文件和目录：
sudo apt clean
第 10 步（可选）：让我们通过使用以下命令删除缓存文件和目录来清理系统。
sudo apt autoclean
结论
通过在/etc/apt/apt.conf.d/位置创建一个干净的缓存文件，可以轻松禁用 Debian 上的 apt 缓存。然后在主位置创建另一个禁用缓存的文件。保存这两个文件以禁用Debian 上的apt 缓存。最好通过“rm -rf”命令或一些可选的 apt 命令删除缓存文件和目录，但如果您在终端上运行它们，这是一种很好的做法。
文章原文出处：https: //linuxhint.com/
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1603180800
Microsoft Exchange, Outlook Under Siege By APTs
New, sophisticated adversaries are switching up their tactics in exploiting enterprise-friendly platforms — most notably Microsoft Exchange, Outlook Web Access (OWA) and Outlook on the Web – in order to steal business credentials and other sensitive data.
Both Microsoft’s Exchange mail server and calendaring server and its Outlook personal information manager web app provide authentication services – and integration with other platforms – that researchers say are prime for attackers to leverage for launching attacks.
Accenture’s 2020 Cyber Threatscape report, released Monday, shed light on how actors are leveraging Exchange and OWA – and evolving their tactics to develop new malware families that target these services, or using new detection evasion techniques.
“Web-facing, data-intense systems and services that typically communicate externally can make it easier for adversaries to hide their traffic in the background noise, while authentication services could open up a credential-harvesting opportunity for cybercriminals,” according to Accenture researchers on Monday.
APTs Flock Exchange, OWA
One threat group that has been targeting Exchange and OWA is what researchers dub “BELUGASTURGEON” (aka Turla or Whitebear). Researchers say that this group operates from Russia, has been active for more than 10 years and is associated with numerous cyberattacks aimed at government agencies, foreign-policy research firms and think tanks across the globe.
The group is targeting these Microsoft services and using them as beachheads to hide traffic, relay commands, compromise e-mail, exfiltrate data and gather credentials for future espionage attacks, said researchers. For instance, they are manipulating legitimate traffic that’s traversing Exchange in order to relay commands or exfiltrate sensitive data.
“Hosts supporting Exchange and associated services frequently relay large volumes of data to external locations— representing a prime opportunity for malicious actors to hide their traffic within this background noise,” said researchers.
Another group, which researchers call SOURFACE (aka APT39 or Chafer), appears to have developed similar techniques to conceal malicious traffic, manipulating local firewalls and proxying traffic over non-standard ports using native commands, tools and functions, researchers said. Researchers said this group has been active since at least 2014 and is known for its cyberattacks on the oil and gas, communications, transportation and other industries in the Australia, Europe, Israel, Saudi Arabia, the U.S. and other regions.
In addition, threat groups are also creating new malware designed to specifically target Exchange and OWA. Researchers said they discovered several malicious files in the wild in 2019 that they assessed “with moderate confidence” were associated to a group called BLACKSTURGEON, used in targeting government and public sector orgs.
That includes a file that seemed like a version of the group’s customized version of the “RULER” tool, which is designed to abuse Microsoft Exchange services. This file exploits the CVE- 2017-11774 Outlook vulnerability, a security-feature bypass vulnerability that affects Microsoft Outlook and enables attackers to execute arbitrary commands, researchers said.
Other Services Under Attack
Cybercriminals are also targeting services that support Exchange and OWA. For instance, client-access servers (CAS), which handle all client connections to Exchange Server 2010 and Exchange 2013, typically operate in web-login portals for services including OWA. Attackers with access to CAS may be able to deploy capabilities to steal user login credentials, researchers said.
“Notably, an advanced persistent threat actor reportedly deployed web shells to harvest credentials from OWA users as they logged in,” they said.
The Windows Internet Information Services (IIS) platform, which supports OWA, is another increasing target. IIS is a web server software created by Microsoft for use with the Windows family. Researchers said they have observed SOURFACE, for instance, deploying custom Active Server Page Extended (ASPX) Web shells to IIS directories within the victim’s OWA environment. These web shells would include discrete file names, to resemble legitimate files on the victim’s system (for instance “login2.aspx” instead of “login.aspx”). And, to evade static detection, they typically contained limited functionality, often only file upload and download or command execution.
#cloud security #government #hacks #vulnerabilities #web security #accenture 2020 cyber threatscape report #advanced threat #aka apt39 #apt #belugasturgeon apt #blacksturgeon apt #chafer #microsoft #microsoft exchange #microsoft outlook #outlook on the web #owa #russia #sourface #tactics #turla apt #whitebear apt #windows internet information services
1679589000
在 Debian 中禁用 APT 缓存
在 Debian 系统中，软件包通常是通过 apt 软件包管理器安装的，它从官方的 Debian 存储库安装软件包。通过 apt 安装的包被移动到缓存目录并在位置'/var/cache/apt/archives'内进行管理。之所以将这些文件放在缓存目录中，是为了保证下次安装一个已经存在的包的依赖包时，不会再安装同一个包；相反，它将从该位置提取包裹。随着时间的流逝，软件包失去了它的价值，总有一天它不再需要系统了。因此，最好在 Debian 系统上禁用 apt 缓存，因为这将有助于释放一些空间。
按照本文的详细指南在 Debian 中禁用apt 缓存。
如何在 Debian 中禁用 APT 缓存
下面给出了在 Debian 中禁用apt 缓存的简单分步说明：
第一步：首先，你必须通过nano编辑器在Debian系统上创建一个00clean-cache-dir文件：
sudo nano /etc/apt/apt.conf.d/00clean-cache-dir第 2 步：在文件中，您必须添加以下行：
DPkg::Post-Invoke {"/bin/rm -f /var/cache/apt/archives/*.deb || true";};
第三步：然后用“CTRL+X”保存干净的缓存文件，加“Y”回车退出。
第 4 步：然后您必须创建另一个名称为“00disbale-cache-files”的文件：
sudo nano 00disable-cache-files第 5 步：在此文件中，添加以下行：
Dir::Cache::srcpkgcache "";
Dir::Cache::pkgcache "";
第 6 步：使用第 3 步保存此文件。
这将禁用Debian 系统上的apt 缓存。
第 7 步：现在 apt 缓存已被禁用，最好使用以下命令清空 Debian 上的“/var/cache/apt/archives”目录：
sudo rm -rf /var/cache/apt/archives
第 8 步（可选）：或者，运行以下命令删除缓存是一个很好的做法：
sudo apt clean --dry-run
第 9 步（可选）：此外，您还可以通过以下命令删除缓存文件和目录：
sudo apt clean
第 10 步（可选）：让我们通过使用以下命令删除缓存文件和目录来清理系统。
sudo apt autoclean
结论
通过在/etc/apt/apt.conf.d/位置创建一个干净的缓存文件，可以轻松禁用 Debian 上的 apt 缓存。然后在主位置创建另一个禁用缓存的文件。保存这两个文件以禁用Debian 上的apt 缓存。最好通过“rm -rf”命令或一些可选的 apt 命令删除缓存文件和目录，但如果您在终端上运行它们，这是一种很好的做法。
文章原文出处：https: //linuxhint.com/
1604166480
How to List Installed Repositories In Ubuntu & Debian
A repository is the collection of packages for a Linux operating system. You can create a central repository containing the actual packages. Then configure your other systems to connect with the main repository. From where, you can install, update packages.
The Ubuntu and other Debian based systems uses APT (Advanced Packages Tool) as package manager. Apt keeps all the configuration files under /etc/apt directory.
This tutorial will help you to list all installed repositories under a Ubuntu or Debian based system via command line.
List Installed Repositories In Ubuntu
The remote repository references are configured in /etc/apt/sources.list file and all files under /etc/apt/sources.list.d/ directory.
Use the following command to list all the configured repositories on apt based system:
sudo grep -rhE ^deb /etc/apt/sources.list*
You will see the output like below:
deb http://mirrors.digitalocean.com/ubuntu/ xenial main restricted
deb-src http://mirrors.digitalocean.com/ubuntu/ xenial main restricted
deb http://mirrors.digitalocean.com/ubuntu/ xenial-updates main restricted
deb-src http://mirrors.digitalocean.com/ubuntu/ xenial-updates main restricted
deb http://mirrors.digitalocean.com/ubuntu/ xenial universe
deb-src http://mirrors.digitalocean.com/ubuntu/ xenial universe
.
.
.
deb http://security.ubuntu.com/ubuntu xenial-security universe
deb-src http://security.ubuntu.com/ubuntu xenial-security universe
deb http://security.ubuntu.com/ubuntu xenial-security multiverse
deb-src http://security.ubuntu.com/ubuntu xenial-security multiverse
Alternatively, you can use apt-cache command to list all repositories. This command will provide also provide more details about the repository.
#debian #apt #debian #repository #ubuntu
1617966120
How To Install PHP 8.0 on Debian 10 / Debian 9
PHP is an open-source programming language used for web development, created by Rasmus Lerdorf in 1994. It is an HTML-embedded scripting language for creating dynamic websites such as blogs, internet forums, e-commerce portals, etc.
In this post, we will see how to install PHP 8.0 on Debian 10 / Debian 9.
Add PHP Repository
SURY, a third-party repository that offers PHP 8.0/7.x for the Debian operating system. Update the repository cache.
sudo apt update
Install the below packages.
sudo apt install -y curl wget gnupg2 ca-certificates lsb-release apt-transport-https
#debian #post #debian 10 #debian 9 #php
1591482900
Upgrade Debian 9 Stretch to Debian 10 Buster From Command Line
Debian 10, codenamed Buster, was released on July 6, 2019. This tutorial is going to you how to upgrade Debian 9 to Debian 10 from command line. You can follow this tutorial on a Debian 9 desktop, or Debian 9 server. As with every Debian release, Debian 10 will be supported for 5 years. The codename “Buster” is named after Andy’s dog in the Toy Story movie.
#debian #debian desktop #debian server #linux