Ref:https://onlinecourses.science.psu.edu/stat464/print/book/export/html/8In front of the one or two samples are examined, now consider the case of k samples, our hypothesis is:
Analysis of Variance (ANOVA)
Assumptions is:
Groups is independent
Distributions is normally distributed
Groups have equal variances
Then our hypothesis is:H0:#x03BC;1=#x03BC;2=#x03BC;3">h0: Μ1=μ2= μ3 H1:at least one not equal">H1: atle
(i) the foregoingYou can modify the IP, or both CS and IP instructions are collectively referred to as transfer instructions .The transfer behavior has the following categories:
When you modify IP only, it is called intra-segment transfer, for example: JMP ax.
Simultaneous modification of CS and IPs is called inter-segment transfer, for example: jmp 1000:0.
because the transfer instruction
IntroductionThe 8086CPU transfer instruction is divided into the following categories:Unconditional transfer instructions (e.g., JMP)Conditional Transfer Directivesloop instructions (e.g. loop)ProcessInterrupt9.1 Operator OffsetThe operator offset is a symbol that is handled by the compiler in assembly language, and its function is to obtain the offset address of the label.9.2 JMP InstructionsJMP is uncondi
ds ss es fs gs) of the sub-defined task from the segment register. general Register status 3. status of the eflags register 4. status of the EIP register 5. the status of the audit register. 6. TR register Status 7. LDTR register status 8. IO ing base address and IO ing (exist in TSS) 9. the stack pointer of privilege level 0, 1, and 2 (exists in TSS) 10. before a task is scheduled, all the preceding information except the TR register status is included in the TSS. Similarly, all content of the
to load the program. There will be many loops in the shell program. When dealing with loops, you can only let the program run forward, basically not let it jump back, you need to think out of the loop. Do not use Peid to query entries. You can track entries in one step to improve the capability of manual entry searching.Load the program with OD.Confirm an entry warning, and the Od prompts the program to shell. If you choose not to continue the analysis.Stop here0040D001 60 pushad first remember
are collectively referred to as transfer commands (We will conduct further research later ). Now we will introduce the simplest command to modify CS and IP addresses:JMP refers to the order.
If you want to modify the Cs and IP content at the same time, the command can be completed in the form of "JMP segment address: Offset address", as shown in figure
JMP 2ae3: 3, after execution: cs = 2ae3h, IP = 0003 H,
Original address: Http://www.cnblogs.com/dennisOne? 8086CPU Transfer Instruction classification
Unconditional transfer instructions (e.g., JMP)
Conditional Transfer Directives
loop instructions (e.g. loop)
Process
Interrupt
? operator offsetOffset in assembly language is the symbol processed by the assembler, its function is to take the offset address of the label.? jmp directi
overflow, and then we'll see how we can exploit the vulnerability.
Vulnerability utilization
To exploit the vulnerability, you must find a string offset that overrides the return address. We can send aaaabbbbccccddd by sending ... Such a combination string looks at exactly where the return address is overwritten. After some analysis, it is learned that at 4056 of the offset is exactly the cover of the function return address. So we're going to design an overflow string like this:
GET/AAAA....|
One, one-factor variance analysisSingle-factor ANOVA has only one grouping variable, so the data looks like a multicolumn data frame, such asGrass Heath Arable1 3 6 192 4 7 33 3 8 84 5 8 85 6 9 96 12 11 117 21 12 128 4 11 119 5 NA 94 Na Na7 Na Na8 Na NaThe basic command for variance analysis is AOC (), and it needs to use the formula syntax, and the data structure is also the Predictor + factor, so for the previous data, if the direct use will be an e
bidirectional table
Chi-square test (chi-square test)The chi-square test is usually used to obtain statistical significance of the relationship between variables, and it examines whether the characteristics shown in the sample are sufficient to reflect the overall characteristics. Chi-square test the difference between the predicted frequency and the actual frequency based on one or more categories of variables in a bidirectional table, which returns the probability of a chi-square distribu
to save the bytecode of the Code function. jmpaddr points to the JMP Instruction address from JMP to the code function. The call [target function] jumps to the address of the JMP [function address] command before JMP is directed to the first address of the target function. Ofsfuncaddr is used to save the offset of the
methods, which is mixed with a lot of flowers and spam commands and then decoded,It is also a bunch of antidebugger, which may be decoded and restored to IAT. It is also a bunch of antidebugger... and finally jumps to the real OEP of the program to deal with such shells.The method is to first find the OEP and then fix the IAT
When the shell jumps to OEP, it is generally a cross-segment jump. There are many jump methods, such as jmp xxxxxxxx,
('PASS ftp' +'\r\n') data = s.recv(1024) s.send('REST' +buffer+'\r\n') s.close()
Restart the FTP server under Immunity debugger (click "debug", then restart or press CTRL + F2) to start the FTP server architecture vulnerability. According to the previous practice, the EIP and ESP buffer must have a format created by metasploit. Copy these values, we will use them to calculate the differences between EIP and ESP registers in bytes.
In this example, the values of EIP and ESP are:
EIP: 69413269ESP:
I have seen some people asking me how to remove the bjfnt 1.2 shell over the past few days. So I wrote this article because the latest version is version 1.3, so I will only talk about the 1.3 shell here, I think 1.2 is simpler than 1.3. of course there are countless experts here, but they don't have time to write something out, so I just have to do it.
There are countless instructions. My total experience is to keep F8 until I can see that a loop cannot go through, and then stop and analyze it.
:
2. Prepare JMP
The above briefly introduces the basic method of assembly-level debugging in VS, and explains how to analyze the machine code using the mov command as an example. With these tools and materials, you can clearly understand the details of the code to be executed within the system. From the preceding section, we can see that the First Command executed by the GetTickCount API is mov. If you can change the Opcode of mov to
Lucifer.; #########################################################################. 386. Model flat, stdcall; -bit memory model option Casemap:none; Case sensitive include \masm32\include\kernel32.inc; ------------------------------------ ; Please read the final usage of the text; ------------------------------------ARGCL PROTO:D Word,:D Word. Code; ######################################################################## #ArgCl proc Argnum:dword, ItemBuffer:D Word local cmdline:D word local c
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