| Alias: | |
| Strain: | - |
| detected when: | |
| where: | |
| Classification: | COM and EXE infector, resident |
| Length: | 63 paragraph(s) |
Preconditions | |
| Operating System(s): | MS-DOS |
| Version/Release: | All models |
| Computer model(s): | PC's |
| Caroname: | Cinderella.II |
Attributes | |
| Easy identification: | |
Type of Infection: | COM: The virus overwrites the beginning of the file, appending the overwritten part after the end of the file. EXE: The virus appends itself to the files Selfrec in memory: Int_21;AH=FA -> AH=F9 Selfrec on disk: (COM) File[0] == {BE 00 01 E8 5D 00 8B 36 1A 01}(EXE) Initial_IP == 32h && Initial_SP == Virus_size+100h |
| Infection Technique: | |
| Infection Trigger: | EXE: (Load) && Current_PSP < Install_PSPCOM: (Load || Open) && Given_Filename_EXT == (case significant) "COM" |
| Storage Media affected: | |
| Interrupts hooked: | 21/4B 21/3D 21/FA 21/F9 24 |
| Stealth: | |
| Tunneling/Selfprot: | |
| Oligo/Polymorphism: | - |
| Encoding Method: | |
| Damage: | Transient: "Cinderella II" written to the screen in an endless loop. Permanent: first 8 sectors under head 1 on cylinder 0 of the first harddisk. (there is an error in the code so this is unlikely to work,AX is meant to contain 0308h but it has the same value as CS: instead). |
| Damage Trigger: | Transient: cumulative infection counter %4k == 0 Permanent: cumulative infection counter %64k == 0 |
| Particularities: | The virus resides above the last MCB when the int24 vector is meant to be restored after infection,it is the int12 vector that is restored instead by mistake. Displayed text: "Cinderella II"; Encrypted Int21 AH=0F9h is used to restore the original program and exit froma COM virus. |
| Similarities: | |
Agents | |
| Countermeasures: | |
| Standard means: | |
Acknowledgements | |
| Location: | Virus Test Center, University Hamburg, FRG |
| Classification by: | Adam David, Frisk Software International |
| Documentation by: | Adam David, Frisk Software International |
| Date: | 20.6.93 |
| Information Source: | Caroentry (autom.converter by S.Freitag) |
(c) 1996 Virus-Test-Center, University of Hamburg