I am facing a very strange situation. Microsoft's Smart Network Data Service is reporting that my IP is attempting to send hundreds of thousands of spams to Microsoft accounts every day.    But, checking my server's logs I have found no indications of that kind of sending volume.  My Qmail queue is 0  None of the recipient email address mentioned in the SNDS report is found in my logs.  No malicious or suspicious script is running on my server  For example, in the sample spam message that I've got from SNDS it mentions "X-PHP-Originating-Script: 1249:phoned.php". No such file is present on my server!!!  So how is this possible?
This is a  about Server Security - Responding to Breach Events (Hacking)   See Also:                  Canonical Version I suspect that one or more of my servers is compromised by a hacker, virus, or other mechanism:   What are my first steps? When I arrive on site should I disconnect the server, preserve "evidence", are there other initial considerations? How do I go about getting services back online? How do I prevent the same thing from happening immediately again? Are there best practices or methodologies for learning from this incident? If I wanted to put a Incident Response Plan together, where would I start? Should this be part of my Disaster Recovery or Business Continuity Planning?   Original Version       2011.01.02 - I'm on my way into work at 9.30 p.m. on a Sunday because our server has been compromised somehow and was resulting in a    attack on our provider. The servers access to the Internet   has been shut down which means over 5-600 of our clients sites are now   down. Now this could be an FTP hack, or some weakness in code   somewhere. I'm not sure till I get there.      How can I track this down quickly? We're in for a whole lot of   litigation if I don't get the server back up ASAP. Any help is   appreciated. We are running Open SUSE 11.0.            2011.01.03 - Thanks to everyone for your help. Luckily I WASN'T the only person responsible for this server, just the nearest. We managed   to resolve this problem, although it may not apply to many others in a   different situation. I'll detail what we did.      We unplugged the server from the net. It was performing (attempting to   perform) a Denial Of Service attack on another server in Indonesia,   and the guilty party was also based there.      We firstly tried to identify where on the server this was coming from,   considering we have over 500 sites on the server, we expected to be   moonlighting for some time. However, with SSH access still, we ran a   command to find all files edited or created in the time the attacks   started. Luckily, the offending file was created over the winter   holidays which meant that not many other files were created on the   server at that time.      We were then able to identify the offending file which was inside the   uploaded images folder within a  website.      After a short cigarette break we concluded that, due to the files   location, it must have been uploaded via a file upload facility that   was inadequetly secured. After some googling, we found that there was   a security vulnerability that allowed files to be uploaded, within the   ZenCart admin panel, for a picture for a record company. (The section   that it never really even used), posting this form just uploaded any   file, it did not check the extension of the file, and didn't even   check to see if the user was logged in.      This meant that any files could be uploaded, including a PHP file for   the attack. We secured the vulnerability with ZenCart on the infected   site, and removed the offending files.      The job was done, and I was home for 2 a.m.            The Moral   - Always apply security patches for ZenCart, or any other CMS system for that matter. As when security updates are released, the whole   world is made aware of the vulnerability.   - Always do backups, and backup your backups.   - Employ or arrange for someone that will be there in times like these. To prevent anyone from relying on a panicy post on Server   Fault.
How do you join or create a server in multiplayer? Why is the even root of a number always positive? Let $n \in \mathbb N$ be a natural number and $a \in \mathbb R$ be a real number. The $n$-th root of the number $a$ is defined as follows:  Case I: $n$ is an odd number. In this case the $n^{\text{th}}$ root of $a$ is defined to be that number $b \in \mathbb R$ such that $b^n = a$.  Case II: $n$ is an even number. In this case the $n^{\text{th}}$ root of $a$ is defined to be that number $b \geq 0$ such that $b^n = a$.  Why is it that when $n$ is even, we only consider $b \geq 0$. For example, both $+2$ and $-2$ squared equal $4$, but when we say the square root of $4$ is $2$. Is there a reason for this? Why must an English learners should know Grammar first? Why must everyone understand Grammar first before learning to speak? First off, sorry for my english. I am currently developing a new website that may be deployed in early 2017. This site may contain user login but that may be shipped later in that year.   Now, I googled about https and I hear mixed opinions, google wants the web in https and may punish those who don't use https in the future. Mozilla will also favor https over http for its Firefox. Let's Encrypt make it for free. So far so good.  What is worrying me is I read that many sites that switched to https suffered much lower revenues of adsense (I read also some terrible things about seo and ranking suffering after switching) and many returned again to http.  How much truth is in the suffering of revenues due to switching to https? My website is still in development so I have actually no links needed to be reindexed. My site isn't a blog type. It mainly provides profiles on local artists in my country.  The problem is I need every penny to cover the server and cdn hosting costs. I can't be sure how much using https will hurt the revenues. Show that $ \sum_{n=2}^m \binom{n}{2} = \binom{m+1}{3}$ I need a hand in showing that $$ \sum_{n=2}^m \binom{n}{2} = \binom{m+1}{3}$$   Thanks in advance for any help. symmetric functions vs symmetric polynomials I am doing my thesis related with symmetric functions and representations.   It is for this reason that I am reading MacDonald's book Symmetric Functions and Hall Polynomials.  When reading chapter 1.2. The ring of symmetric functions, he also talks about symmetric polynomials. And he compares both notions and sometimes treats them as equivalent but sometimes not. Does anyone have a clearer explanation about what is the difference (if there are differences)?  So, what is the difference between symmetric functions and symmetric polynomials? Directing graph such that any outdegree would be at most 2 Let $G=(V,E)$ be a graph. Suppose that for every subgraph $G'=(V',E') , G' \subset G$, we have $|E'| \le 2|V'|$. Show it's possible to direct $G$ such that any outdegree would be at most $2$.   I tried proving it by induction. I've realized that the minimum degree at any subgraph of $G$ is at most 4. I tried removing the vertex $v_0$ with the minimal degree at a certain subgraph from the original graph, claiming that the graph from the remaining vertexes can be directed as required. How can I include the vertex $v_0$ in the new directed graph such that any outdegree would still be at most 2? Thanks What autofocus zone selection mode should I use for action/event shooting? I have a Canon 7D, and typically shoot everything I do in its single-point autofocus zone select mode, because I usually want fine control over exactly what the camera is focusing on and I often find that its two automatic focus zone select modes don't focus on what I want in focus.  For most of the photography I do, this is fine -- I have enough time that I can compose the shot the way I want, use the joystick on the back to select the right focus point, and take the shot at my leisure.  However, recently I've been doing more event/action photography, and I've been running into issues with this mode of operation.  Too often, I will see a person start to do something interesting, but my autofocus point is not in the right place -- so by the time I get the camera up, adjust the settings, and move the autofocus point, the opportunity to take the shot has passed.  My question is, what autofocus zone selection mode and workflow should I use for this type of photography?  I could use the 5-zone partial-auto mode (which gives me a choice of top, middle, bottom, left, or right, and then the camera chooses the points within my selected region), but I find that the time needed to switch in between that mode and the single-point mode is similarly prohibitive, and I have to hope that the camera chooses the right thing to focus on. What exactly does Perl's "bless" do? I understand one uses the "bless" keyword in Perl inside a class's "new" method:  sub new {     my $self = bless { };     return $self; }       But what exactly is "bless" doing to that hash reference ? End of javascript sidebar workarounds? (Salesforce Classic / Aloha) Reading through this doc:      We replaced the rich text editor in HTML Area home page components   with a new version that supports more markup but doesn’t allow HTML to   be manually entered.      In Summer ’15 we will start removing unsupported code from HTML Area   home page components. As a result, components that contain JavaScript,   CSS, iframes, or other unsupported markup might stop working properly.   To use JavaScript or other advanced HTML elements in your home page   component, we recommend that you use a Visualforce Area component   instead.   With Visualforce homepage component the best we could do is design fancy home page components, which has not been the big use of sidebar amongst developers. How do we do the fancy hack we do today using html components since visualforce is hosted in a different domain will the sidebar hacks even work after summer 15?     You can include JavaScript in your Visualforce page, but because the   component is rendered in an iframe on the home page layout, the   JavaScript can’t interact with the page that contains the component.   Finally why this move :(? Twice now I've tried pan frying fillets of white fish (Swai and Flouder) in olive oil and butter.  Both times the fish has disintegrated into unsightly mush.  Is there some technique I'm missing?  How can I pan fry without the fish falling apart? I used to say "sharp sign" to refer to the # sign.   Today a friend told me that the correct term is number sign or hash sign or even just hash.  What is the difference between these options and what's the correct usage of the names for this sign? Find the sum of finite series $S=\sum_{k=1}^{2015}{(-1)^{\frac{k(k+1)}{2}}}k$ consider the following subsets of complex plane $$\Omega_1=\left\{c\in\Bbb C:\begin{bmatrix}1&amp;c\\\bar c&amp;1\\ \end{bmatrix}\text{ is non-negative definite } \right\} $$  $$\Omega_2= \left\{c\in\Bbb C:         \begin{bmatrix}         1 &amp; c &amp; c \\         \bar c &amp; 1 &amp; c \\         \bar c &amp; \bar c &amp; 1 \\         \end{bmatrix} \text{ is non-negative definite } \right\}$$  Let $$\bar D=\{z\in\Bbb C:|z|\le1\}$$ Then 1) $\Omega_1=\bar D,\Omega_2=\bar D$  2). $\Omega_1\neq\bar D, \Omega_2=\bar D$  3). $\Omega_1=\bar D, \Omega_2\neq\bar D$  4). $\Omega_1\neq\bar D, \Omega_2\neq\bar D$  How to proceed? Thank you. The derivative of $x!$ and its continuity is the factorial of fractions and negative numbers defined? If yes, then what is its graph? Also please find its domain.  Our teacher said the factorial of a fraction is the fraction itself. He also said the graph is continuous but could not determine the derivative of $x!$. Delete all files except files with the extension pdf in a directory So that I could resize the window to a certain size from within Terminal. Remove Indentation for a Single Paragraph Is there a way to remove the indentation at the beginning of a paragraph for a single paragraph.  I know I could do  \setlength{\parindent}{0cm} This is my paragraph.  Blah blah blah. \setlength{\parindent}{default}   Where default is whatever the default indentation is for the document class I am using (part of the problem is that I don't know what this default value is).  I feel as if there should be a better way to accomplish this than by the above method.  I am looking for a solution of the form:  \noindent This is my paragraph.  Blah blah blah.   Is there a way to do this, or will I have to resort to the former method?  If I have to resort to the former method, what is the default indentation value for the amsart document class? Formula for determinant of block matrix with commuting blocks On , I saw the following formula  $$\det\begin{bmatrix}A &amp; B\\ C &amp; D\end{bmatrix} = \det(AD-BC)$$  if $C$ and $D$ commute. Is this always true?   Or is there a good counter example for each $2 \times 2$ block matrices? If random variables are drawn from an identical distribution, why doesn't this guarantee they are independent?