الجمعة، 1 أكتوبر 2010
الأحد، 26 سبتمبر 2010
IV. Metatags
A couple of years ago <meta> tags were the primary tool for search engine optimization and there was a direct correlation between what you wrote there and your position in search results. However, algorithms got better and today the importance of metadata is decreasing day by day, especially with Google. But still some search engines show metadata (under the clickable link in search results), so users can read what you have written and if they think it is relevant, they might go to your site. Also, some of the specialized search engines still use the metatags when ranking your site.
The meta Description tag is are one more way for you to write a description of your site, thus pointing search engines to what themes and topics your Web site is relevant to. It does not hurt to include at least a brief description, so don't skip it. For instance, for the dog adoption site, the meta Description tag could be something like this: <Meta Name=“Description” Content=“Adopting a dog saves a life and brings joy to your house. All you need to know when you consider adopting a dog.”>
A potential use of the meta Keywords tags is to include a list of keywords that you think are relevant to your pages. The major search engines will not take this into account but still it is a chance for you to emphasize your target keywords. You may consider including alternative spellings (or even common misspellings of your keywords) in the meta Keywords tag. For instance, if I were to write the meta keywords tag for the dog adoption site, I would do it like that: <Meta name=“Keywords” Content=“adopt, adoption, dog, dogs, puppy, canine, save a life, homeless animals”>. It is a small boost to search engine top ranking but why miss the chance?
The meta Robots tag deserves more attention. In this tag you specify the pages that you do NOT want crawled and indexed. It happens that on your site you have contents that you need to keep there but you don't want it indexed. Listing this pages in the meta Robots tag is one way to exclude them (the other way is by using a robots.txt file and generally this is the better way to do it) from being indexed.
III. Links – Another Important SEO Item
1. Why Links Are Important
Probably the word that associates best with Web is “links”. That is what hypertext is all about – you link to pages you like and get linked by pages that like your site. Actually, the Web is woven out of interconnected pages and spiders follow the links, when indexing the Web. If not many sites link to you, then it might take ages for search engines to find your site and even if they find you, it is unlikely that you will have high rankings because the quality and quantity of links is part of the algorithms of search engines for calculating relevancy.
2. Inbound and Outbound Links
Put in layman's terms, there are two types of links that are important for SEO – inbound and outbound links. Outbound links are links that start from your site and lead to another one, while inbound links, or backlinks, come from an external site to yours, e.g. if a.com links to mydomain.com, the link from a.com is an inbound link for mydomain.com.
Backlinks are very important because they are supposed to be a measure of the popularity of your site among the Web audience. It is necessary to say that not all backlinks are equal. There are good and bad backlinks. Good backlinks are from reputable places - preferably from sites with a similar theme. These links do boost search engine ranking. Bad backlinks come from suspicious places – like link farms – and are something to be avoided. Well, if you are backlinked without your knowledge and consent, maybe you should drop the Webmaster a line, asking him or her to remove the backlink.
If you are not heavily backlinked, don't worry - buying links is an established practice and if you are serious about getting to the top, you may need to consider it. But before doing this, you should consider some free alternatives. For instance, some of the good places where you can get quality backlinks are Web directories like http://dmoz.org or http://dir.yahoo.com.
First, look for suitable sites to backlink to you using the Backlinks Builder . After you identify potential backlinks, it's time to contact the Web master of the site and to start negotiating terms. Sometimes you can agree to a barter deal – i.e. a link exchange – they will put on their site N links to your site and you will put on your site N links to their site - but have in mind that this is a bad, risky deal and you should always try to avoid it.
Internal links (i.e. links from one page to another page on the same site) are also important but not as much as backlinks. In this connection it is necessary to say, that using images for links might be prettier but it is a SEO killer. Instead of having buttons for links, use simple text links. Since search engines spider the text on a page, they can't see all the designer miracles, like gradient buttons or flash animations, so when possible, either avoid using them, or provide a meaningful textual description in the <alt> tag, as described next.
3. Anchor text
Anchor text is the most important item in a backlink. While it does matter where a link comes from (i.e. a reputable place or a link farm), what matters more is the actual text the link starts from. Put simply, anchor text is the word(s) that you click on to open the hyperlink – e.g. if we have the best search engine, than “the best search engine” is the anchor text for the hyperlink to google.com. You see that you might have a backlink from a valuable site but if the anchor text is something like “an example of a complete failure”, you will hardly be happy with it.
When you check your backlinks, always check what their anchor text is and if there is a keyword in it. It is a great SEO boost to have a lot of backlinks from quality sites and the anchor text to include our keywords. Check the anchor text of inbound backlinks is with the Backlink Anchor Text Analyzer tool . Besides the anchor text itself, the text around it is also important.
Anchor text is the most important item in a backlink. While it does matter where a link comes from (i.e. a reputable place or a link farm), what matters more is the actual text the link starts from. Put simply, anchor text is the word(s) that you click on to open the hyperlink – e.g. if we have the best search engine, than “the best search engine” is the anchor text for the hyperlink to google.com. You see that you might have a backlink from a valuable site but if the anchor text is something like “an example of a complete failure”, you will hardly be happy with it.
When you check your backlinks, always check what their anchor text is and if there is a keyword in it. It is a great SEO boost to have a lot of backlinks from quality sites and the anchor text to include our keywords. Check the anchor text of inbound backlinks is with the Backlink Anchor Text Analyzer tool . Besides the anchor text itself, the text around it is also important.
4. Link Practices That Are To Be Avoided
Similar to keyword stuffing, purchasing links in bulk is a practice to be avoided. It gets suspicious if you bartered 1000 links with another site in a day or two. What is more, search engines keep track of link farms (sites that sell links in bulk) and since bought links are a way to manipulate search results, this practice gets punished by search engines. So avoid dealing with link farms because it can cause more harm than do good. Also, outbound links from your site to known Web spammers or “bad guys” are also to be avoided.
As mentioned, link exchange is not a clean deal. Even if it boosts your ranking, it can have many other negative aspects in the long run. First, you do not know if the other party will keep their promise – i.e. they might remove some of the links to you. Second, they might change the context the link appears into. Third, it is really suspicious if you seem to be “married” to another site and 50% or more of your inbound and outbound links are from/to this direction.
When links are concerned, one aspect to have in mind is the ratio between inbound and outbound links. Generally speaking, if your outbound links are ten times your inbound links, this is bad but it also varies on a case by case basis. If you have a site that links to news sources or has RSS feeds, then having many outbound links is the inevitable price of fresh content.
Similar to keyword stuffing, purchasing links in bulk is a practice to be avoided. It gets suspicious if you bartered 1000 links with another site in a day or two. What is more, search engines keep track of link farms (sites that sell links in bulk) and since bought links are a way to manipulate search results, this practice gets punished by search engines. So avoid dealing with link farms because it can cause more harm than do good. Also, outbound links from your site to known Web spammers or “bad guys” are also to be avoided.
As mentioned, link exchange is not a clean deal. Even if it boosts your ranking, it can have many other negative aspects in the long run. First, you do not know if the other party will keep their promise – i.e. they might remove some of the links to you. Second, they might change the context the link appears into. Third, it is really suspicious if you seem to be “married” to another site and 50% or more of your inbound and outbound links are from/to this direction.
When links are concerned, one aspect to have in mind is the ratio between inbound and outbound links. Generally speaking, if your outbound links are ten times your inbound links, this is bad but it also varies on a case by case basis. If you have a site that links to news sources or has RSS feeds, then having many outbound links is the inevitable price of fresh content.
تحذير مهم جدا: خطر سرقة ايميلك ومعلوماتك بضغطة زر
لقد رأيت في الاونة الاخيرة العديد من الرسائل المرسلة من ايميلات منها بأسم شركات معروفة مثل شركة YAHOO او GOOGLE MAIL او Fcebook او بنوك مثل Egold و آخرها من LibertyReserve.com , او غيرها من الشركات و البنوك تطلب من الناس ان يقوموا بتفعيل ايميلاتهم واشتراكاتهم مالم فسيتم اغلاق حساباتهم بسبب فشل في النظام، وهو في الحقيقة صفحات مزورة تعرف بـ Phishing ,وهي صفحات مزورة واحيانا يوهموا الناس انهم حصلوا على مبالغ معينه فبمجرد ان يقوم الشخص بالضغط على الرابط المرفق مع الرسالة يتم تحويلهم الى صفخات اخرى او يكون هنالك في الاغلب رسالة تقول لك بأن الصفحة غير موجودة او ان الصفحة لايمكن تحميلها الان بسبب الضغط في النظام او الموقع لذا حاول مجددا، وفي الحقيقة انه قد تم ارسال ايميلك و رقمك السري وحساباتك وكل مالديك من معلومات سرية وخاصة الى ايميل الشخص المخترق الذي ارسل الرسالة ومنها يتم سرقة جميع ارصدتك في البنوك او التشهير بأسمك في مواقع الاختراق واللعب بمحتويات بريدك او مراسلة اصدقائك بأسمك و خداعهم او ابتزازهم والعديد من الاشياء التي لايمكنكم تخيلها.
ملاحظة: اغلب الشركات والبنوك لا تطلب منك تأكيد رقمك السري او Psaaword على الاطلاق بعد عمل البريد او الايميل.
لذا ارجوا منكم ان تحذروا الرسائل الغريبه والمشبوههة وان تزودوا اصحابكم واهلكم عن الموضوع وتحذروهم، وكذلك لا تنسوا ان تزودوا انفسكم بالمعلومات اللازمة عن الاختراق واحدث طرق الاختراق.
واذا اردتم ان تستفسروا عن مواضيع الاختراق او اي موضوع في مجال تقنية المعلومات ارجوا ان تتفاعلوا معي و تطرحوا مواضيعكم و نقاشاتكم في مدونتي ليتم مناقشتها ومشاركة الافكار والمعلومات وتبادل الخبرات فيما بيننا لنشر المعرفة للجميع.
ارجوا الا تنسوني من الدعاء
Is your PC a sitting duck for hackers?
How confident are you that your computer is safe from an online attack?
Chances are you rely on vendors like Microsoft and Apple to let you know when a security update is ready to be installed. (Google updates systems automatically.)
But until a patch is released, that hole--known as a zero-day vulnerability--in effect makes your computer a sitting duck for anyone who writes an exploit for it and bothers to distribute it via e-mails and drive-by downloads on Web sites.
EEye Digital Security launched a Web site yesterday that lists current zero-day vulnerabilities and offers an archive on ones that have been patched. The Zero Day Tracker compiles information on publicly disclosed security holes and provides details on them including what software they affect, how severe they are, the potential impact and suggestions for workarounds and other protection techniques.
Marc Maiffret, co-founder and chief technology officer of eEye, describes the free site as a "one-stop shop" for zero-day information.
"For the longest time the only company that would notify you about zero-days was Microsoft, and recently Adobe has started doing that," he said. "But there are still many other companies that have zero-day vulnerabilities that go unreported."
The most widely used database of software vulnerabilities is the National Vulnerability Database sponsored by the Department of Homeland Security's National Cyber Security Division/US-CERT and run by the National Institute of Standards and Technology. There is also the Open Source Vulnerability Database, the US-CERT Vulnerability Notes Database and one run by SecurityFocus. But you have to do some digging on the sites to find the vulnerabilities that are unpatched.
Zero Day Tracker lists the outstanding unpatched holes with the most recent at the top. There are 21 current zero-days, all of them from 2010 except for one from 2006 and one from 2005. The oldest extant unpatched hole was first disclosed in November 2005 and affects Windows 2000. Patched zero-days are archived by year and date back to 2005.
"Microsoft, as some might expect, has the largest amount of unpatched zero day vulnerabilities in 2010," Maiffret said. Microsoft also dominates previous years too, not surprisingly, with increasing numbers for Adobe Systems as the years progress and only a few for Apple among them.
Those statistics are cursory and likely to change as eEye works to populate the archives.
Meanwhile, asked to comment on the dearth of Apple listings, Maiffret said that reflects on Apple's market being much smaller than Windows and does not mean that Macintosh software is more secure.
"There are significantly fewer zero-day vulnerabilities for Apple compared to Microsoft and Microsoft-related applications, but it's definitely not about Mac not having vulnerabilities," he said. Attackers prefer to spend their time and energy targeting the 90 or so percent of computers on the Internet running Windows, he added. (For more on the Mac-PC comparison, see "In their words: Experts weigh in on Mac vs. PC security.")
Recently, Adobe rushed out a patch for a zero-day vulnerability in Flash Player, and Microsoft released an emergency patch for one that exploited a Windows hole to spread the Stuxnet worm, which targets industrial control and critical infrastructure systems. Stuxnet exploited three other Windows vulnerabilities, one of which Microsoft patched last week and two others that are pending.
The Zero Day Tracker site also will include information on unpatched mobile software, which is a growing field. "One of the last iPhone jailbreak hacks out there was actually leveraging a vulnerability within PDF (portable document format) processing on the iPhone," Maiffret said. "That's an example of a zero-day vulnerability on the mobile platform."
In addition to offering a handy resource for people looking for zero-day information, Maiffret hopes that publicizing vulnerabilities on the Zero Day Tracker site will motivate vendors to patch them more quickly. "We want to put pressure on software vendors," he said.
The company is gathering its information from vendors, security e-mail lists, and by monitoring underground and overseas forums where malicious hackers brag about finding or exploiting holes in popular programs. "One (tip) we got was based on conversations on a Chinese message board," Maiffret said.
Often, when announcing a security hole vendors will attempt to assuage customer fears by announcing that attacks targeting the vulnerability have not yet been seen in the wild. But it's usually only a matter of time before an exploit surfaces, particularly if the software is something popular like Windows, Adobe Reader or Internet Explorer, according to Maiffret. "Often it's within the same day," he said.
For instance, Microsoft on Friday warned of a serious hole in its ASP.NET framework used to create Web sites and said it was not aware of any attacks using it. On Monday, the company updated its security advisory on the vulnerability to say that it was aware of "limited, active attacks" using the hole.
Exploits can go undetected for months, or even longer. For example, it's unclear how long the Operation Aurora attack that targeted Google and dozens of other companies via an unknown hole in Internet Explorer was going on. Google disclosed it in January 2010 and said it uncovered it the previous month. But one analysis said it was first tested in the wild five months before then, although it might not have been targeting the same companies at that time. Several days after Google announced the attacks, Microsoft confirmed the IE hole and a week later patched it.
"The vulnerability was being used before the industry knew about it," Maiffret said. "There are a huge number of attacks we don't know about and we typically learn about accidentally."
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