AS Gelar Perang Cyber Global, Pengacara Protes

-Amerika Serikat (AS) sebagai negara adidaya dunia mulai melirik perang cyber bersekala internasional. Pentagon selaku pusat komando perang di AS menekankan diberlakukannya perang dunia cyber tanpa batas di tingkat internasional.

Komandan perang cyber di Pentagon menuntut pelimpahan kekuasaan penuh untuk memulai perang dunia terhadap berbagai situs dan jaringan komputer di berbagai penjuru dunia demi menjaga kepentingan Washington.

Demikian dilaporkan Koran Washington Post seperti dikutip Fars News Sabtu (6/11).
Para pengacara dan pakar hukum di pemerintahan Barack Obama yang kurang percaya terhadap legalitas operasi cyber memprotes program Pentagon.

Jenderal. Keith B. Alexander, komandan bidang perang cyber di Departemen Pertahanan AS (Pentagon) yang juga menjabat ketua Dinas Keamanan Nasional menghendaki kekuatan manuver yang memadai bagi sektor ini guna memulai operasi di segala bidang di dunia maya

AS Gelar Perang Cyber Global, Pengacara Protes

-Amerika Serikat (AS) sebagai negara adidaya dunia mulai melirik perang cyber bersekala internasional. Pentagon selaku pusat komando perang di AS menekankan diberlakukannya perang dunia cyber tanpa batas di tingkat internasional.

Komandan perang cyber di Pentagon menuntut pelimpahan kekuasaan penuh untuk memulai perang dunia terhadap berbagai situs dan jaringan komputer di berbagai penjuru dunia demi menjaga kepentingan Washington.

Demikian dilaporkan Koran Washington Post seperti dikutip Fars News Sabtu (6/11).
Para pengacara dan pakar hukum di pemerintahan Barack Obama yang kurang percaya terhadap legalitas operasi cyber memprotes program Pentagon.

Jenderal. Keith B. Alexander, komandan bidang perang cyber di Departemen Pertahanan AS (Pentagon) yang juga menjabat ketua Dinas Keamanan Nasional menghendaki kekuatan manuver yang memadai bagi sektor ini guna memulai operasi di segala bidang di dunia maya

JENAYAH CYBER

SERDANG: Sifat tamak dan cepat teruja dengan tawaran lumayan dalam Internet seperti skim cepat kaya dikenal pasti menjadi punca utama menyebabkan jenayah siber semakin bermaharajalela, sehingga sesiapa saja boleh menjadi mangsa dan mengalami kerugian dalam sekelip mata.

Ketua Pegawai Eksekutif CyberSecurity Malaysia, Lt Kol (B) Husin Jazri, berkata melalui penyelidikan dan siasatan pihaknya mendapati sifat tamak sesetengah individu menjadi penyumbang besar kepada kes jenayah siber.

Menurutnya, individu yang mudah teruja, ditambah dengan sifat ingin cepat senang dan kaya dalam tempoh singkat tanpa usaha sewajarnya boleh menyebabkan semakin tinggi peluangnya untuk menjadi mangsa kepada penipuan di alam siber.

“Kami dapati ancaman terbesar kepada jenayah siber ini ialah diri kita sendiri iaitu perasaan tamak dari dalam diri serta kurangnya pengetahuan dan kemahiran mengenai teknologi maklumat.

“Inilah punca utama kita dieksploitasi dan membuka peluang kepada penjenayah siber untuk menipu, lebih-lebih lagi bagi individu yang gagal mendisiplinkan dirinya,” katanya ketika ditemui selepas menerima kunjungan Timbalan Menteri Sains, Teknologi dan Inovasi, Fadillah Yusof, di pejabatnya di Seri Kembangan, di sini, semalam.

)The shape of a local-area network (LAN) or other communications system. Topologies are either physical or logical.

There are four principal topologies used in LANs.

bus topology: All devices are connected to a central cable, called the bus or backbone. Bus networks are relatively inexpensive and easy to install for small networks. Ethernet systems use a bus topology.

ring topology : All devices are connected to one another in the shape of a closed loop, so that each device is connected directly to two other devices, one on either side of it. Ring topologies are relatively expensive and difficult to install, but they offer high bandwidth and can span large distances.

star topology: All devices are connected to a central hub. Star networks are relatively easy to install and manage, but bottlenecks can occur because all data must pass through the hub.

tree topology: A tree topology combines characteristics of linear bus and star topologies. It consists of groups of star-configured workstations connected to a linear bus backbone cable.

ROKET AIR

Cara Mudah Membuat Roket Air
AMARAN : Permainan Roket Air ini memerlukan pengawasan ibu bapa atau orang dewasa, kerana
ianya berbahaya jika ianya tidak dikendalikan dengan betul. Ianya harus dimainkan di kawasan
lapang, jauh dari orang ramai. Ianya berbahaya ketika Pelancaran Roket dan ketika Roket jatuh
selepas dilancarkan.

BAHAN YANG DIPERLUKAN
1. Pam tayar (pompa ban)
2. RoketROKET AIR
3. Pelancar Roket

ROKET
Roket boleh dibuat daripada botol air terpakai saiz 500 ml atau 1.5 L. Lagi besar lagi tinggi pergi
roket dan lebih masa diperlukan untuk mengepam. Botol air diubahsuai menggunakan beberapa
botol atau plastik supaya mendapat bentuk roket. Sayap diperlukan pada bawah roket untuk
penerbangan yang baik. Gunakan tape atau apa yang sesuai untuk menyambungkan bahagian roket.
Muncung roket juga perlu berat sedikit (seberat duit 50 sen), letak plastesin atau apa-apa yang
sesuai dan selamat pada dalam muncung roket supaya roket boleh pergi tegak.

PELANCAR
Pelancar roket boleh dipegang atau dibuat tapak pelancar. Pelancar roket dibuat dari paip PVC yang
biasa digunakan untuk memasang paip dirumah. Sambungkan hujung paip pada penutup paip yang
ditebuk lubang untuk dipasang NAT (vavle) tayar. Nat tayar ini boleh didapati pada tiub tayar
motosikal yang terpakai.

Pelancar roket boleh dipasang pada tapak pelancar yang diperbuat dari kayu terpakai. Ikat tali pada

muncung botol roket untuk dikuncikan pada tapak pelancar

PELANCARAN ROKET
Masukkan air dalam roket.
Pastikan apabila roket dimasukkan pada pelancar, air lebih kurang 40% dari isipadu botol. Kalau
lebih roket menjadi berat dan tak pergi tinggi.
Pegang hujung roket (untuk pelancar tanpa kunci) atau kuncikan roket pada tapak pelancar.
Mulakan pam angin ke dalam pelancar roket. Cuba dahulu 2-3 pam dan lepaskan roket untuk
mendapatkan sukatan bilangan pam yang sesuai. Jangan pam terlalu banyak angin , kerana boleh
menyebabkan roket atau pelancar pecah.
Pastikan tiada sesiapa berhampiran tapak pelancaran roket dan tempat roket dijangka akan jatuh.
Cuba dengan botol kecil dahulu 500ml sebelum mencuba dengan botol besar 1.5ml. Botol kecil
boleh pergi setinggi 100 meter , sementara botol besar boleh pergi setinggi 200 meter.

SELAMAT MENCUBA DAN BERHATI-HATI

JADIKAN INI SEBAGAI AKTIVITI BERILMU DAN AKTIVITI KELUARGA

Influenza A virus subtype H1N1

Influenza A (H1N1) virus is a subtype of influenza A virus and was the most common cause of human influenza (flu) in 2009. Some strains of H1N1 are endemic in humans and cause a small fraction of all influenza-like illness and a small fraction of all seasonal influenza. H1N1 strains caused a few percent of all human flu infections in 2004–2005.^[1] Other strains of H1N1 are endemic in pigs (swine influenza) and in birds (avian influenza).

In June 2009, the World Health Organization declared the new strain of swine-origin H1N1 as a pandemic. This strain is often called swine flu by the public media. This novel virus spread worldwide and had caused about 17,000 deaths by the start of 2010.

HIV

Human immunodeficiency virus (HIV) is a lentivirus (a member of the retrovirus family) that causes acquired immunodeficiency syndrome (AIDS),^[1][2] a condition in humans in which the immune system begins to fail, leading to life-threatening opportunistic infections. Infection with HIV occurs by the transfer of blood, semen, vaginal fluid, pre-ejaculate, or breast milk. Within these bodily fluids, HIV is present as both free virus particles and virus within infected immune cells. The four major routes of transmission are unsafe sex, contaminated needles, breast milk, and transmission from an infected mother to her baby at birth (vertical transmission). Screening of blood products for HIV has largely eliminated transmission through blood transfusions or infected blood products in the developed world.

HIV infection in humans is considered pandemic by the World Health Organization (WHO). Nevertheless, complacency about HIV may play a key role in HIV risk.^[3][4] From its discovery in 1981 to 2006, AIDS killed more than 25 million people.^[5] HIV infects about 0.6% of the world's population.^[5] In 2005 alone, AIDS claimed an estimated 2.4–3.3 million lives, of which more than 570,000 were children. A third of these deaths are occurring in Sub-Saharan Africa, retarding economic growth and increasing poverty.^[6] According to current estimates, HIV is set to infect 90 million people in Africa, resulting in a minimum estimate of 18 million orphans.^[7] Antiretroviral treatment reduces both the mortality and the morbidity of HIV infection, but routine access to antiretroviral medication is not available in all countries.^[8]

HIV infects primarily vital cells in the human immune system such as helper T cells (to be specific, CD4⁺ T cells), macrophages, and dendritic cells. HIV infection leads to low levels of CD4⁺ T cells through three main mechanisms: First, direct viral killing of infected cells; second, increased rates of apoptosis in infected cells; and third, killing of infected CD4⁺ T cells by CD8 cytotoxic lymphocytes that recognize infected cells. When CD4⁺ T cell numbers decline below a critical level, cell-mediated immunity is lost, and the body becomes progressively more susceptible to opportunistic infections.

Most untreated people infected with HIV-1 eventually develop AIDS. These individuals mostly die from opportunistic infections or malignancies associated with the progressive failure of the immune system.^[9] HIV progresses to AIDS at a variable rate affected by viral, host, and environmental factors; most will progress to AIDS within 10 years of HIV infection: some will have progressed much sooner, and some will take much longer.^[10][11] Treatment with anti-retrovirals increases the life expectancy of people infected with HIV. Even after HIV has progressed to diagnosable AIDS, the average survival time with antiretroviral therapy was estimated to be more than 5 years as of 2005.^[12] Without antiretroviral therapy, someone who has AIDS typically dies within a year.^[13]

Network topology

Network topology is defined as the interconnection of the various elements (links, nodes, etc.) of a computer network.[1][2] Network Topologies can be physical or logical. Physical Topology means the physical design of a network including the devices, location and cable installation. Logical topology refers to the fact that how data actually transfers in a network as opposed to its physical design.
Topology can be considered as a virtual shape or structure of a network. This shape actually does not correspond to the actual physical design of the devices on the computer network. The computers on the home network can be arranged in a circle shape but it does not necessarily mean that it presents a ring topology.
Any particular network topology is determined only by the graphical mapping of the configuration of physical and/or logical connections between nodes. The study of network topology uses graph theory. Distances between nodes, physical interconnections, transmission rates, and/or signal types may differ in two networks and yet their topologies may be identical.
A Local Area Network (LAN) is one example of a network that exhibits both a physical topology and a logical topology. Any given node in the LAN has one or more links to one or more nodes in the network and the mapping of these links and nodes in a graph results in a geometrical shape that may be used to describe the physical topology of the network. Likewise, the mapping of the data flow between the nodes in the network determines the logical topology of the network. The physical and logical topologies may or may not be identical in any particular network.

Network architecture

Network architecture is the design of a communications network. It is a framework for the specification of a network's physical components and their functional organization and configuration, its operational principles and procedures, as well as data formats used in its operation.
In computing, the network architecture is a characteristics of a computer network. The most prominent architecture today is evident in the framework of the Internet, which is based on the Internet Protocol Suite.
In telecommunication, the specification of a network architecture may also include a detailed description of products and services delivered via a communications network, as well as detailed rate and billing structures under which services are compensated.
In distinct usage in distributed computing, network architecture is also sometimes used as a synonym for the structure and classification of distributed application architecture, as the participating nodes in a distributed application are often referred to as a network. For example, the applications architecture of the public switched telephone network (PSTN) has been termed the Advanced Intelligent Network. There are any number of specific classifications but all lie on a continuum between the dumb network (e.g., Internet) and the intelligent computer network (e.g., the telephone network). Other networks contain various elements of these two classical types to make them suitable for various types of applications. Recently the context aware network, which is a synthesis of the two, has gained much interest with its ability to combine the best elements of both.

Computer network

A computer network, often simply referred to as a network, is a collection of computers and devices connected by communications channels that facilitates communications among users and allows users to share resources with other users. Networks may be classified according to a wide variety of characteristics. This article provides a general overview of types and categories and also presents the basic components of a network.

Functions of the Operating System

An operating system is a software component that acts as the core of a computer system. It performs various functions and is essentially the interface that connects your computer and its supported components. In this article, we will discuss the basic functions of the operating system, along with security concerns for the most popular types.

Operating system

An operating system is the software on a computer that manages the way different programs use its hardware, and regulates the ways that a user controls the computer.[1][2] Operating systems are found on almost any device that contains a computer with multiple programs—from cellular phones and video game consoles to supercomputers and web servers. Some popular modern operating systems for personal computers include Microsoft Windows, Mac OS X, and Linux[3] (see also: list of operating systems, comparison of operating systems).
Because early computers were often built for only a single task, operating systems did not exist in their proper form until the 1960s.[4] As computers evolved into being devices that could run different programs in succession, programmers began putting libraries of common programs (in the form of computer code) onto the computer in order to avoid duplication and speed up the process. Eventually, computers began being built to automatically switch from one task to the next. The creation of runtime libraries to manage processing and printing speed came next, which evolved into programs that could interpret different types of programming languages into machine code. When personal computers by companies such as Apple Inc., Atari, IBM and Amiga became popular in the 1980s, vendors began adding features such as software scheduling and hardware maintenance.
An operating system can be divided into many different parts. One of the most important parts is the kernel, which controls low-level processes that the average user usually cannot see: it controls how memory is read and written, the order in which processes are executed, how information is received and sent by devices like the monitor, keyboard and mouse, and deciding how to interpret information received by networks. The user interface is the part of the operating system that interacts with the computer user directly, allowing them to control and use programs. The user interface may be graphical with icons and a desktop, or textual, with a command line. Another similar feature is an Application programming interface, which is a set of services and code libraries that let applications interact with one another, as well as the operating system itself. Depending on the operating system, many of these components may not be considered an actual part. For example, Windows considers its user interface to be part of the operating system, while many versions of Linux do not.

Secondary storage

Secondary storage (or external memory) differs from primary storage in that it is not directly accessible by the CPU. The computer usually uses its input/output channels to access secondary storage and transfers the desired data using intermediate area in primary storage. Secondary storage does not lose the data when the device is powered down—it is non-volatile. Per unit, it is typically also two orders of magnitude less expensive than primary storage. Consequently, modern computer systems typically have two orders of magnitude more secondary storage than primary storage and data is kept for a longer time there.
In modern computers, hard disk drives are usually used as secondary storage. The time taken to access a given byte of information stored on a hard disk is typically a few thousandths of a second, or milliseconds. By contrast, the time taken to access a given byte of information stored in random access memory is measured in billionths of a second, or nanoseconds. This illustrates the very significant access-time difference which distinguishes solid-state memory from rotating magnetic storage devices: hard disks are typically about a million times slower than memory. Rotating optical storage devices, such as CD and DVD drives, have even longer access times. With disk drives, once the disk read/write head reaches the proper placement and the data of interest rotates under it, subsequent data on the track are very fast to access. As a result, in order to hide the initial seek time and rotational latency, data are transferred to and from disks in large contiguous blocks.
When data reside on disk, block access to hide latency offers a ray of hope in designing efficient external memory algorithms. Sequential or block access on disks is orders of magnitude faster than random access, and many sophisticated paradigms have been developed to design efficient algorithms based upon sequential and block access . Another way to reduce the I/O bottleneck is to use multiple disks in parallel in order to increase the bandwidth between primary and secondary memory.[2]
Some other examples of secondary storage technologies are: flash memory (e.g. USB flash drives or keys), floppy disks, magnetic tape, paper tape, punched cards, standalone RAM disks, and Iomega Zip drives.
The secondary storage is often formatted according to a file system format, which provides the abstraction necessary to organize data into files and directories, providing also additional information (called metadata) describing the owner of a certain file, the access time, the access permissions, and other information.
Most computer operating systems use the concept of virtual memory, allowing utilization of more primary storage capacity than is physically available in the system. As the primary memory fills up, the system moves the least-used chunks (pages) to secondary storage devices (to a swap file or page file), retrieving them later when they are needed. As more of these retrievals from slower secondary storage are necessary, the more the overall system performance is degraded.

Primary storage

Primary storage (or main memory or internal memory), often referred to simply as memory, is the only one directly accessible to the CPU. The CPU continuously reads instructions stored there and executes them as required. Any data actively operated on is also stored there in uniform manner.
Historically, early computers used delay lines, Williams tubes, or rotating magnetic drums as primary storage. By 1954, those unreliable methods were mostly replaced by magnetic core memory, which was still rather cumbersome. Undoubtedly, a revolution was started with the invention of a transistor, that soon enabled then-unbelievable miniaturization of electronic memory via solid-state silicon chip technology.
This led to a modern random-access memory (RAM). It is small-sized, light, but quite expensive at the same time. (The particular types of RAM used for primary storage are also volatile, i.e. they lose the information when not powered).
As shown in the diagram, traditionally there are two more sub-layers of the primary storage, besides main large-capacity RAM:
Processor registers are located inside the processor. Each register typically holds a word of data (often 32 or 64 bits). CPU instructions instruct the arithmetic and logic unit to perform various calculations or other operations on this data (or with the help of it). Registers are technically among the fastest of all forms of computer data storage.
Processor cache is an intermediate stage between ultra-fast registers and much slower main memory. It's introduced solely to increase performance of the computer. Most actively used information in the main memory is just duplicated in the cache memory, which is faster, but of much lesser capacity. On the other hand it is much slower, but much larger than processor registers. Multi-level hierarchical cache setup is also commonly used—primary cache being smallest, fastest and located inside the processor; secondary cache being somewhat larger and slower.
Main memory is directly or indirectly connected to the central processing unit via a memory bus. It is actually two buses (not on the diagram): an address bus and a data bus. The CPU firstly sends a number through an address bus, a number called memory address, that indicates the desired location of data. Then it reads or writes the data itself using the data bus. Additionally, a memory management unit (MMU) is a small device between CPU and RAM recalculating the actual memory address, for example to provide an abstraction of virtual memory or other tasks.
As the RAM types used for primary storage are volatile (cleared at start up), a computer containing only such storage would not have a source to read instructions from, in order to start the computer. Hence, non-volatile primary storage containing a small startup program (BIOS) is used to bootstrap the computer, that is, to read a larger program from non-volatile secondary storage to RAM and start to execute it. A non-volatile technology used for this purpose is called ROM, for read-only memory (the terminology may be somewhat confusing as most ROM types are also capable of random access).
Many types of "ROM" are not literally read only, as updates are possible; however it is slow and memory must be erased in large portions before it can be re-written. Some embedded systems run programs directly from ROM (or similar), because such programs are rarely changed. Standard computers do not store non-rudimentary programs in ROM, rather use large capacities of secondary storage, which is non-volatile as well, and not as costly.
Recently, primary storage and secondary storage in some uses refer to what was historically called, respectively, secondary storage and tertiary storage.[1]

Purpose of storage

Many different forms of storage, based on various natural phenomena, have been invented. So far, no practical universal storage medium exists, and all forms of storage have some drawbacks. Therefore a computer system usually contains several kinds of storage, each with an individual purpose.
A digital computer represents data using the binary numeral system. Text, numbers, pictures, audio, and nearly any other form of information can be converted into a string of bits, or binary digits, each of which has a value of 1 or 0. The most common unit of storage is the byte, equal to 8 bits. A piece of information can be handled by any computer whose storage space is large enough to accommodate the binary representation of the piece of information, or simply data. For example, using eight million bits, or about one megabyte, a typical computer could store a short novel.
Traditionally the most important part of every computer is the central processing unit (CPU, or simply a processor), because it actually operates on data, performs any calculations, and controls all the other components.
Without a significant amount of memory, a computer would merely be able to perform fixed operations and immediately output the result. It would have to be reconfigured to change its behavior. This is acceptable for devices such as desk calculators or simple digital signal processors. Von Neumann machines differ in that they have a memory in which they store their operating instructions and data. Such computers are more versatile in that they do not need to have their hardware reconfigured for each new program, but can simply be reprogrammed with new in-memory instructions; they also tend to be simpler to design, in that a relatively simple processor may keep state between successive computations to build up complex procedural results. Most modern computers are von Neumann machines.
In practice, almost all computers use a variety of memory types, organized in a storage hierarchy around the CPU, as a trade-off between performance and cost. Generally, the lower a storage is in the hierarchy, the lesser its bandwidth and the greater its access latency is from the CPU. This traditional division of storage to primary, secondary, tertiary and off-line storage is also guided by cost per bit.

Langkah dan Tahap Format Ulang Hard Disk :

1. Back up file penting anda yang ada pada hardisk karena perintah format ini akan menghapus semua file yang ada di hard disk anda. Jika anda punya cd-rw drive atau dvd-rw drive anda bisa membuat cadangan dengan cara membakar file anda ke dalam cd atau dvd, atau kalau tidak punya CD RW, gunakan saja flash disk, itu pun kalau cukup untuk menampung data-data anda.2. Lalu langkah selanjutnya adalah membuat windows boot disk / rescue disk pada disket floppy 1.4 MB. Disket ini bertujuan untuk booting langsung ke disket tidak melalui harddisk anda. Istilahnya anda akan menggunakan os microsoft dos yang ada pada disket yang anda buat. 3. Kalau tidak punya DOS, coba pinjam atau beli CD yang berisi DOS, saya dulu mendapatkannya di tempat kursus, jadi tidak perlu membuat sistem di disket. Tinggal masukkan saja, pakai untuk bootable.4. Ganti Setting Bios Ketika komputer dinyalakan anda harus langsung masuk ke tampilan bios untuk setting pilihan urutan boot. Ketika komputer baru dinyalakan, tekan tombol delete sampai bios muncul di layar monitor komputer anda. Ganti urutan booting dengan urutan pertama floppy disk.5. Format Hard Disk. Setelah urutan boot di bios diganti, anda masukkan disket kemudian restart komputer anda. Nanti komputer anda akan otomatis membooting dari disket tersebut dan pilih boot without cd-rom supaya proses booting bisa lebih cepat. Setelah masuk ke command prompt a:\ , ketik format c: lalu tekan enter. Hal yang sama bisa diterapkan ke partisi harddik yang lain disesuaikan dengan jumlah partisi anda yang ada. Jika anda punya partisi 3 buah maka tambah perintah format d: dan format e:.6. Kalau anda menggunakan CD bootable, tinggal masukkan saja, otomatis akan muncul DOS begitu di booting.Kini harddisk anda menjadi seperti baru kembali.

Strategi penyalinan

Supaya dapat menyalin diri, virus harus dibenarkan untuk melaksanakan kodnya dan menulis pada ingatan. Atas alasan ini, banyak virus melekat pada fail boleh laku yang merupakan sebahagian atur cara yang sah. Jika seseorang pengguna mencuba melaksanakan atur cara yang terjangkit, kod virus akan dilaksanakan lebih dahulu.
Virus-virus boleh dibahagikan kepada dua jenis, bersandarkan tindakannya apabila dilaksanakan:
Virus bukan huni dengan serta-merta akan mencari-cari perumah yang lain yang boleh dijangkiti dan selepas menjangkitinya, akan memindahkan kawalan kepada atur-atur cara penggunaan yang terjangkit.
Virus huni tidak mencari perumah apabila ia dilaksanakan tetapi sebaliknya, memuat diri ke dalam ingatan dan memindahkan kawalannya kepada atur cara perumah. Virus huni masih tetap aktif di latar belakang dan akan menjangkiti perumah-perumah yang baru apabila fail-fail itu dicapai oleh atur cara yang lain atau oleh sistem pengendalian pada dirinya.
[sunting] Virus bukan huni
Virus bukan huni boleh dianggap sebagai terdiri daripada dua modul, iaitu "modul pencarian" dan "modul penyalinan". Modul pencarian bertanggungjawab untuk mencari fail baru untuk dijangkiti. Bagi setiap fail boleh laku yang baru yang ditemukan, modul pencarian akan memanggil modul penyalinan untuk menjangkiti fail itu.
Untuk virus-virus yang mudah, tugas-tugas penyalin adalah seperti yang berikut:
Menyemak adakah fail boleh laku itu telah dijangkiti (jika ia, kembali ke modul pencarian);
Melampirkan kod virus pada fail boleh laku;
Simpan titik permulaan fail boleh laku;
Tukarkan titik permulaan fail boleh laku supaya ia menunjuk ke lokasi permulaan kod virus yang baru sahaja disalin;
Simpan lokasi permulaan yang lama supaya virus akan menyimpang ke lokasi itu selepas ia dilaksanakan;
Simpan perubahan dalam fail boleh laku;
Tutup fail yang terjangkit; dan
Kembali ke modul pencarian supaya ia boleh mencari fail yang baru untuk dijangkiti oleh penyalin.
[sunting] Virus huni
Virus huni mengandungi modul penyalinan yang serupa dengan modul yang digunakan oleh virus bukan huni, tetapi ia tidak digelar sebagai modul pencarian. Sebaliknya, virus ini memuat modul penyalinan ke dalam ingatan apabila ia dilaksanakan dan memastikan bahawa modul ini akan dilaksanakan setiap kali sistem pengendalian dipanggil untuk melakukan tugas-tugas yang tertentu, umpamanya apabila sistem pengendalian itu melaksanakan sesuatu fail. Dalam kes ini, virus itu akan menjangkiti setiap atur cara yang sesuai yang dilaksanakan oleh komputer.
Virus-virus huni kekadang dibahagikan kepada dua kategori, iaitu penjangkit cepat dan penjangkit lambat. Penjangkit cepat direka untuk menjangkiti sebanyak fail yang mungkin, umpamanya ia boleh menjangkiti setiap fail perumah yang dicapai. Ini akan menimbulkan masalah yang khusus untuk perisian anti-virus kerana pengimbas virus akan mencapai setiap fail perumah yang berpotensi di dalam komputer apabila ia mengimbas seluruh sistem. Jika pengimbas virus gagal mengesan virus sebegitu yang wujud di dalam ingatan, virus itu boleh "menggendong" pengimbas virus dan dengan itu, menjangkiti semua fail yang diimbas. Penjangkit cepat bergantung kepada kadar penjangkitannya yang cepat untuk merebak. Kelemahan kaedah ini adalah bahawa penjangkitan banyak fail akan menyebabkannya mudah dikesan kerana virus itu akan memperlahankan komputer atau melakukan banyak tindakan yang menimbulkan kesangsian yang boleh dikesan oleh perisian anti-virus.
Penjangkit lambat sebaliknya direka untuk menjangkiti perumahnya sekali sekala. Umpamanya, sesetengah penjangkit lambat hanya menjangkiti fail apabila fail itu disalin. Penjangkit lambat direka semata-mata untuk mengelakkan pengesanan dengan membatasi tindakannya. Ia tidak banyak memperlahankan komputer dan jarang mencetuskan perisian anti-virus yang mengesan tindakan atur cara yang menimbulkan kesangsian. Walaupun demikian, pendekatan penjangkit lambat kelihatan tidak begitu berjaya.

Mengapa orang mencipta virus komputer

Berbeza dengan virus biologi, virus komputer:
tidak mengembangkan diri;
tidak wujud secara spontan dan tidak dicipta oleh pepijat atur cara biasa; ia dicipta secara sengaja oleh para pengaturcara atau orang yang menggunakan perisian mencipta virus; dan
hanya boleh membuat apa-apa yang ditetapkan oleh pengaturcara.
Para pencipta virus mempunyai berbagai-bagai alasan untuk mencipta dan menyebarkan perisian jahat. Virus-virus telah dicipta sebagai projek penyelidikan, usikan, dan laku musnah, serta juga untuk menyerang produk syarikat-syarikat tertentu, menyebarkan pesanan politik, dan memperoleh keuntungan daripada pencurian identiti, perisian pengintipan (spyware), dan pemerasan kriptovirus.
Sesetengah penulis virus menganggap ciptaan mereka sebagai seni, dan melihat penulisan atur cara virus sebagai suatu hobi yang kreatif. Tambahan pula, banyak penulis virus menentang rutin-rutin yang ditulis semata-mata untuk melakukan pemusnahan. Selain itu, banyak penulis virus juga menganggap sistem-sistem yang diserang oleh mereka sebagai suatu cabaran intelektual atau satu masalah logik untuk diselesaikan. Ini berganda apabila permainan kucing dengan tikus itu terhadap perisian anti-virus dijangka.
Sesetengah virus bertujuan untuk merupakan "virus baik". Ia menyebarkan perbaikan kepada atur-atur cara yang dijangkitinya, atau menghapuskan virus-virus yang lain. Walaupun demikian, virus-virus sebegini adalah agak jarang. Ia masih menelan sumber sistem, dan mungkin akan menjejaskan sistem yang dijangkitinya tanpa sengaja serta juga kekadangnya dijangkiti oleh virus yang lain dan bertindak pula sebagai vektor untuk virus jahat. Tanpa disengajakan, atur-atur cara "virus baik" yang tidak ditulis dengan teliti juga boleh menjadi virus yang mendatangkan keburukan pada dirinya (umpamanya, 'virus baik' yang sebegini boleh salah mengecam fail sasaran dan dengan itu, salah menghapuskan fail sistem). Tambahan pula, ia biasanya bertindak tanpa meminta sebarang kebenaran daripada pemilik komputer. Oleh sebab kod penyalinan diri menimbulkan banyak kerumitan, adakah sesuatu virus yang bertujuan baik boleh menyelesaikan masalah dengan cara yang lebih baik, berbanding dengan atur cara biasa yang tidak menyalin diri, boleh dipersoalkan.
Dengan pendek kata, tidak adanya satu jawapan yang tunggal yang mungkin merangkumi seluruh demografi penulis virus yang begitu luas. Dalam kebanyakan bidang kuasa, pembebasan virus komputer (serta juga cecacing) merupakan suatu jenayah komputer. Sila lihat juga rencana Berita BBC: Mengapa orang mencipta virus komputer.

virus

Virus komputer adalah nama yang diambil dari virus biologi, merupakan program komputer yang berupaya menyalin dirinya sendiri dan menjangkiti komputer tanpa kebenaran ataupun pengetahuan pengguna. Bagaimanapun perkataan virus biasanya digunakan bagi merujuk kepada pelbagai jenis perisian perosak yang berlainan. Virus yang asal mungkin mengubah suai salinannya atau salinan itu sendiri yang mengubah suai dirinya, seperti dalam virus metamorf. Virus hanya boleh tersebar apabila hosnya sampai ke komputer lain, contohnya melalui rangkaian atau perantara mudah alih seperti cakera liut, cakera padat atau pemacu kilat USB. Selain itu, virus juga boleh merebak dengan menjangkiti fail pada sistem fail rangkaian atau mana-mana sistem fail yang dicapai komputer lain.
Sesetengah virus direka untuk menjejaskan komputer dengan merosakkan atur cara, menghapuskan fail, atau memformat semula cakera keras, manakala virus-virus yang lain direka bukan untuk merosakkan apa-apa, tetapi hanya untuk menyalin diri dan mungkin untuk menonjolkan kewujudannya melalui pemaparan teks, video, atau pesanan audio. Walaupun virus yang kedua ini tidak berbahaya, ia juga boleh menimbulkan masalah kepada pengguna komputer kerana ia menelan ingatan komputer yang digunakan oleh atur cara yang sah. Oleh yang demikian, ia seringnya mengakibatkan tindakan yang tidak menentu dan boleh mengakibatkan kerosakan sistem. Selain itu, banyak virus juga mengandungi pepijat yang boleh mengakibatkan kerosakan sistem dan kehilangan data.
Virus komputer kekadangnya dikelirukan dengan cecacing komputer dan kuda Trojan. Kedua-dua ini berbeza dari segi bahawa cecacing boleh merebak ke komputer yang lain tanpa memerlukannya dipindahkan sebagai sebahagian fail perumah, manakala kuda Trojan adalah fail yang kelihatan tidak berbahaya sehingga dilaksanakan. Berbeza dengan virus, kuda Trojan juga tidak memasukkan kodnya ke dalam fail-fail komputer yang lain.
Banyak komputer peribadi kini dihubungkan dengan internet serta rangkaian kawasan setempat dan dengan itu, memudahkan perebakan virus. Ia mengambil kesempatan yang diberikan oleh perkhidmatan rangkaian seperti sistem-sistem Jaringan Sejagat, e-mel, dan pengongsian fail untuk merebak dan dengan itu, mengaburi perbezaan antara virus dengan cecacing komputer. Tambahan pula, sesetengah sumber menggunakan istilah alternatif yang mentakrifkan virus sebagai mana-mana bentuk perisian jahat penyalinan diri.

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