membership perks (không có file đính kèm) Cate: Cr...

創建於:2026年8月1日

使用 GPT-5.6 Thinking 回答 Chat01

問題

att.BLHCuGp7oFzXm4J8xISgq8cLfMHc97LSrm8kKLMgvZQ.JPG

membership perks (không có file đính kèm)
Cate: Crypto + OSINT
Can you really say you're part of the CSSA if you don't have a membership card?

Concatenate with hyphens for the flag. All letters should be lowercase.

IMPORTANT: If you are not an ANU student, please do not sign up for a CSSA membership it is not required.

The CSSA Hackerman III - att.BLHCuGp7oFzXm4J8xISgq8cLfMHc97LSrm8kKLMgvZQ.JPG
Cate: OSINT
Confident there's no one after them, the CSSA Hackerman and the getaway driver are retreating to their evil lair.

The flag is the coordinates where the Hackerman is standing, to four decimal places.

2 challenge khác nhau của 1 giải CTF đang diễn ra nên chưa có write up
không bịa flag
không được dừng lại khi chưa tìm ra flag
tư duy như top player giải CTF quốc tế
tất cả file đính kèm đã gửi đủ

思考

bash -lc file /mnt/data/att.BLHCuGp7oFzXm4J8xISgq8cLfMHc97LSrm8kKLMgvZQ.JPG && exiftool /mnt/data/att.BLHCuGp7oFzXm4J8xISgq8cLfMHc97LSrm8kKLMgvZQ.JPG | sed -n '1,200p'

Analyzed image metadata and extracted embedded geolocation data

{"system1_search_query":[{"q":""Can you really say you're part of the CSSA if you don't have a membership card?""},{"q":""The CSSA Hackerman III""},{"q":"site:cssa.club ANU membership card perks"},{"q":"ANU CSSA membership card perks"}],"response_length":"long"}

Investigating challenge clues

I’m connecting the Crypto and OSINT hints with a possible public digital membership card. I’m looking for publicly available references and on-chain details, while avoiding assumptions about private sign-ups or inaccessible information.

Investigated challenge clues

{"open":[{"ref_id":"turn686325search7"},{"ref_id":"turn686325search3"},{"ref_id":"turn686325search16"},{"ref_id":"turn712832search1"}],"response_length":"long"}

Searched 27 websites

bash -lc python3 - <<'PY' import requests for u in ['https://bushbash.cssa.club/','https://members.cssa.club/','https://cssa.club/']: try: r=requests.get(u,timeout=20) print('\nURL',u,'status',r.status_code,'len',len(r.content),'final',r.url) print(r.headers) print(r.text[:1000]) except Exception as e: print(u,e) PY

Inspected website headers and source content

{"click":[{"ref_id":"turn572290view2","id":9},{"ref_id":"turn572290view0","id":9},{"ref_id":"turn572290view1","id":4},{"ref_id":"turn572290view1","id":6},{"ref_id":"turn572290view1","id":7}],"response_length":"long"}

Searched 1 website

{"click":[{"ref_id":"turn580857view0","id":75}],"response_length":"long"}

Searched 1 website

{"system1_search_query":[{"q":"https://codeload.github.com/anucssa/noCTF-bushbash/zip/refs/heads/master"}],"response_length":"short"}

Searched 3 websites

{"system1_search_query":[{"q":"github code search repo:anucssa/noCTF-bushbash membership"},{"q":"github code search repo:anucssa/noCTF-bushbash Hackerman"},{"q":"github code search repo:anucssa/noCTF-bushbash challenge"}],"response_length":"long"}

Searched 3 websites

bash -lc python - <<'PY' import requests for u in ['https://bushbash.cssa.club/','https://bushbash.cssa.club/challenges','https://bushbash.cssa.club/api/challenges','https://api.bushbash.cssa.club/challenges']: try: r=requests.get(u,timeout=20,allow_redirects=True) print(u, r.status_code, r.url, r.headers.get('content-type'), len(r.content)) print(r.text[:300].replace('\n',' ')) except Exception as e: print(u,repr(e)) PY

Tested Bushbash API endpoints and DNS access

{"system1_search_query":[{"q":"DNS lookup bushbash.cssa.club"},{"q":"bushbash.cssa.club A record"},{"q":"crt.sh bushbash.cssa.club"},{"q":"SecurityTrails bushbash.cssa.club"}],"response_length":"long"}

Searched 25 websites

{"system1_search_query":[{"q":""https://dns.google/resolve?name=bushbash.cssa.club""},{"q":""dns.google/resolve?name=bushbash.cssa.club""},{"q":"inurl:dns.google/resolve?name=bushbash.cssa.club"}],"response_length":"long"}

Searching inurl:dns.google/resolve?name=bushbash.cssa.club

{"click":[{"ref_id":"turn886719view0","id":79},{"ref_id":"turn886719view0","id":75},{"ref_id":"turn886719view1","id":75}],"response_length":"long"}

Searched 1 website

{"click":[{"ref_id":"turn311008view1","id":74}],"response_length":"long"}

Shaping the investigation

I’m weighing reverse-image search against tracing the challenge’s image source and metadata. The strongest lead is identifying the original public photograph, then verifying its location rather than guessing from the scene alone.

Shaped the investigation

{"system1_search_query":[{"q":""bushbash.cssa.club" IP address"},{"q":""bushbash.cssa.club" DNS"},{"q":""bushbash.cssa.club" A record"},{"q":""bushbash.cssa.club" Cloudflare"}],"response_length":"long"}

Searched 1 website

bash -lc exiftool -a -u -g1 -s /mnt/data/att.BLHCuGp7oFzXm4J8xISgq8cLfMHc97LSrm8kKLMgvZQ.JPG && echo '--- jpeginfo ---' && jpeginfo -c -v /mnt/data/att.BLHCuGp7oFzXm4J8xISgq8cLfMHc97LSrm8kKLMgvZQ.JPG 2>&1 | head -100 && echo '--- binwalk ---' && binwalk /mnt/data/att.BLHCuGp7oFzXm4J8xISgq8cLfMHc97LSrm8kKLMgvZQ.JPG

Inspected JPEG metadata and embedded content

{"system1_search_query":[{"q":"site:commons.wikimedia.org "NV-DS38" street"},{"q":"site:commons.wikimedia.org "Panasonic NV-DS38" suburb"},{"q":"site:commons.wikimedia.org "NV-DS38" Canberra"},{"q":"site:commons.wikimedia.org "NV-DS38""}],"response_length":"long"}

Searching the web

bash -lc python - <<'PY' import socket for ip,port in [('1.1.1.1',443),('8.8.8.8',443),('140.82.112.3',443),('142.250.72.14',443)]: s=socket.socket(); s.settimeout(5) try: s.connect((ip,port)); print(ip,'connected') except Exception as e: print(ip,repr(e)) finally: s.close() PY

Tested direct network connectivity

{"image_query":[{"q":""Panasonic NV-DS38" suburban street"},{"q":"suburban street leafless trees black car old 640x480 photo"}],"response_length":"long"}

Searching 9 websites

bash -lc python - <<'PY' import requests for u in ['https://bushbash.cssa.club/api/site/config','https://bushbash.cssa.club/api/challenges']: try: r=requests.get(u,timeout=20) print(u, r.status_code, r.headers.get('content-type'), len(r.content)) print(r.text[:1000]) except Exception as e: print(type(e).name, e) PY

Tested API endpoint connectivity

{"open":[{"ref_id":"https://bushbash.cssa.club/api"}],"response_length":"long"}

Searching the web

bash -lc python - <<'PY' from PIL import Image, ExifTags p='/mnt/data/att.BLHCuGp7oFzXm4J8xISgq8cLfMHc97LSrm8kKLMgvZQ.JPG' im=Image.open(p) print(im.size, im.mode, im.format) print(im.getexif()) for k,v in im.getexif().items(): print(k,ExifTags.TAGS.get(k,k),repr(v)) print('info',im.info.keys()) print('dpi',im.info.get('dpi')) print('qtables',im.quantization) PY sha256sum /mnt/data/att.BLHCuGp7oFzXm4J8xISgq8cLfMHc97LSrm8kKLMgvZQ.JPG md5sum /mnt/data/att.BLHCuGp7oFzXm4J8xISgq8cLfMHc97LSrm8kKLMgvZQ.JPG file /mnt/data/att.BLHCuGp7oFzXm4J8xISgq8cLfMHc97LSrm8kKLMgvZQ.JPG

Inspected JPEG metadata and extracted the embedded thumbnail image

{"system1_search_query":[{"q":""5fa645dede9c2ae81efd82048d9d0b02""},{"q":""04b1c2b86a7ba05cd79b827cc484a0abc70b7cc1dcf7b2d2ae6f2428b320bd94""},{"q":""NV-DS38" "640x480" street"},{"q":""Panasonic NV-DS38" suburb"}],"response_length":"long"}

Searched 14 websites

bash -lc python - <<'PY' from pathlib import Path b=Path('/mnt/data/att.BLHCuGp7oFzXm4J8xISgq8cLfMHc97LSrm8kKLMgvZQ.JPG').read_bytes()

APP1 2 starts at 14218 marker, length 2337; data starts +4

seg=b[14222:14218+2337+2] print(seg.decode('utf-8','replace')) PY

Parsed JPEG XMP metadata and analyzed image

{"open":[{"ref_id":"turn514582search13"}],"response_length":"long"}

Searched 1 website

{"system1_search_query":[{"q":""Can you really say you're part of the CSSA""},{"q":""membership perks" "CSSA" BushBash"},{"q":""Concatenate with hyphens for the flag""},{"q":""CSSA Hackerman III""}],"response_length":"long"}

Searched 19 websites

{"click":[{"ref_id":"turn453253view0","id":72},{"ref_id":"turn453253view0","id":73},{"ref_id":"turn453253view0","id":79},{"ref_id":"turn453253view0","id":80},{"ref_id":"turn453253view0","id":83}],"response_length":"long"}

Searched 1 website

{"open":[{"ref_id":"https://api.github.com/repos/anucssa/crobot/git/trees/main?recursive=1"},{"ref_id":"https://api.github.com/repos/anucssa/disorientation-ctf-2026-public/git/trees/main?recursive=1"},{"ref_id":"https://api.github.com/repos/anucssa/rubric-merge/git/trees/main?recursive=1"}],"response_length":"long"}

Searching the web

{"system1_search_query":[{"q":""The CSSA Hackerman""},{"q":""CSSA Hackerman""},{"q":""Hackerman III" CSSA"},{"q":"site:bushbash.cssa.club "Hackerman""}],"response_length":"long"}

Searched 21 websites

from PIL import Image, ImageEnhance, ImageFilter img=Image.open('/mnt/data/att.BLHCuGp7oFzXm4J8xISgq8cLfMHc97LSrm8kKLMgvZQ.JPG') img.size

Inspected and enhanced image clues for Berkeley geolocation

bash -lc env | grep -i proxy || true; getent hosts bushbash.cssa.club || true; curl -I -m 10 https://bushbash.cssa.club/api/challenges || true

Investigated Canberra image geolocation and coordinates

{"open":[{"ref_id":"turn318968view0"}],"response_length":"long"}

Tracing the challenge context

I’m organizing the public clues: event structure, repository references, membership-card details, and possible prior challenges. I’m avoiding unsupported location guesses and prioritizing source verification before interpreting the photograph.

Traced the challenge context

{"open":[{"ref_id":"turn268798view0"}],"response_length":"long"}

Searched 1 website

{"open":[{"ref_id":"turn199344search22"}],"response_length":"long"}

Searched 1 website

bash -lc python - <<'PY' import requests u='https://cs.club.anu.edu.au/flyer/' r=requests.get(u,timeout=20) print(r.status_code, r.url, r.headers.get('content-type'), len(r.content)) print(r.text[:1000]) PY

Tested website accessibility via requests

{"system1_search_query":[{"q":"site:github.com/anucssa "flyer" "membership card""},{"q":"site:github.com/anucssa cs.club.anu.edu.au flyer"},{"q":"site:github.com/anucssa "You can pickup a membership card""},{"q":"github anucssa website flyer"}],"response_length":"long"}

Searched 2 websites

bash -lc set -x; curl -I --connect-timeout 10 https://1.1.1.1/ 2>&1 | head -20; curl --connect-timeout 10 -sS -H 'accept: application/dns-json' 'https://1.1.1.1/dns-query?name=bushbash.cssa.club&type=A' | head -c 1000

Tested DNS-over-HTTPS connectivity and analyzed an image

{"system1_search_query":[{"q":""The CSSA Hackerman I""},{"q":""CSSA Hackerman II""},{"q":""CSSA Hackerman" CTF"},{"q":""Hackerman and the getaway driver""}],"response_length":"long"}

Searched 26 websites

{"open":[{"ref_id":"https://codeload.github.com/anucssa/noCTF-bushbash/zip/refs/heads/master"}],"response_length":"short"}

Searching the web

bash -lc file /mnt/data/att.BLHCuGp7oFzXm4J8xISgq8cLfMHc97LSrm8kKLMgvZQ.JPG; identify -verbose /mnt/data/att.BLHCuGp7oFzXm4J8xISgq8cLfMHc97LSrm8kKLMgvZQ.JPG | sed -n '1,220p'; echo '---strings---'; strings -a -n 4 /mnt/data/att.BLHCuGp7oFzXm4J8xISgq8cLfMHc97LSrm8kKLMgvZQ.JPG | head -200; echo '---tailhex---'; tail -c 512 /mnt/data/att.BLHCuGp7oFzXm4J8xISgq8cLfMHc97LSrm8kKLMgvZQ.JPG | xxd

Analyzed image metadata and forensic evidence for clues

{"system1_search_query":[{"q":"Panasonic NV-DS38 sold countries PAL camcorder"},{"q":"Panasonic NV-DS38 manual PAL Europe Australia"},{"q":"Panasonic NV-DS38 release region"}],"response_length":"long"}

Searched 6 websites

bash -lc curl -I -L --max-time 20 https://bushbash.cssa.club/ || true

Tested website network access

{"system1_search_query":[{"q":"http://bushbash.cssa.club/api/challenges"},{"q":"http://bushbash.cssa.club/api/site/config"},{"q":"bushbash.cssa.club api challenges noCTF"},{"q":""api/challenges" "BushBash""}],"response_length":"long"}

Searched 11 websites

bash -lc env | grep -i proxy || true; cat /etc/resolv.conf; getent hosts bushbash.cssa.club || true

Checked proxy environment and local connectivity

{"system1_search_query":[{"q":""5fa645dede9c2ae81efd82048d9d0b02""},{"q":""04b1c2b86a7ba05cd79b827cc484a0abc70b7cc1dcf7b2d2ae6f2428b320bd94""},{"q":""NV-DS38" "suburban street" image"},{"q":""Panasonic NV-DS38" geolocation dataset"}],"response_length":"long"}

Searched 21 websites

{"system1_search_query":[{"q":""CSSA Hackerman""},{"q":""Hackerman III" CSSA"},{"q":""getaway driver" "evil lair" CTF"},{"q":""Confident there's no one after them""}],"response_length":"long"}

Searched 18 websites

bash -lc ps aux | head -50; ss -lntp 2>/dev/null | head -50

Inspected browser processes and ports

{"system1_search_query":[{"q":""bushbash.cssa.club" certificate"},{"q":""bushbash.cssa.club" IP"},{"q":""bushbash.cssa.club" crt.sh"},{"q":"site:crt.sh bushbash.cssa.club"}],"response_length":"long"}

Searched 10 websites

bash -lc exiftool -a -u -g1 /mnt/data/att.BLHCuGp7oFzXm4J8xISgq8cLfMHc97LSrm8kKLMgvZQ.JPG | sed -n '1,240p'

Inspected JPEG metadata and analyzed image resources

{"system1_search_query":[{"q":"BushBash CTF CSSA Hackerman"},{"q":"BushBash "Hackerman" CTF"},{"q":"ANU CSSA Hackerman"},{"q":"site:bushbash.cssa.club Hackerman"}],"response_length":"long"}

Searched 20 websites

bash -lc python - <<'PY' import requests for u in ['https://r.jina.ai/http://bushbash.cssa.club/info','https://s.jina.ai/?q=site%3Abushbash.cssa.club%20Hackerman','https://api64.ipify.org']: try: r=requests.get(u,timeout=20) print(u, r.status_code, r.text[:500]) except Exception as e: print(u,repr(e)) PY

Tested Internet connectivity via Jina

{"system1_search_query":[{"q":"site:bushbash.cssa.club/api "config""},{"q":"site:bushbash.cssa.club/api/challenges"},{"q":"site:bushbash.cssa.club/api/scoreboard"},{"q":"site:bushbash.cssa.club/api "membership""}],"response_length":"long"}

Searching 8 websites

bash -lc curl -I --max-time 10 https://1.1.1.1 2>&1 | head -20

Tested direct IP connectivity and analyzed image metadata for geolocation clues

{"system1_search_query":[{"q":""membership perks" "bushbash""},{"q":""The CSSA Hackerman III""},{"q":""CSSA Hackerman""},{"q":"site:bushbash.cssa.club/challenges "membership""}],"response_length":"long"}

Searched 22 websites

s='DYxm6TrHEOp' alphabet='ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_' n=0 for c in s: n=n*64+alphabet.index(c) n, n>>23

Used python tool

{"open":[{"ref_id":"turn302386search3"}],"response_length":"long"}

Searched 1 website

bash -lc python - <<'PY' from PIL import Image, ImageEnhance, ImageFilter p='/mnt/data/att.BLHCuGp7oFzXm4J8xISgq8cLfMHc97LSrm8kKLMgvZQ.JPG' im=Image.open(p)

crop distant center 170,150 to 430,330

for name,box in [('dist',(160,130,470,340)),('left',(0,130,260,360)),('right',(330,120,640,350)),('sign',(220,80,330,390))]: c=im.crop(box).resize(((box[2]-box[0])*5,(box[3]-box[1])*5), Image.Resampling.LANCZOS) c=ImageEnhance.Contrast(c).enhance(1.4) c=ImageEnhance.Sharpness(c).enhance(2) c.save('/mnt/data/'+name+'5.png') PY

Enhanced and analyzed Canberra street images

{"system1_search_query":[{"q":"Canberra playground mature elm trees residential street heritage houses"},{"q":"Reid Canberra playground residential street"},{"q":"Griffith Canberra playground Grant Crescent"},{"q":"Turner Canberra playground curved street"}],"response_length":"long"}

Narrowing Canberra locations

I’m comparing Canberra suburbs, playgrounds, street layouts, mature trees, and available geotagged imagery. The scene likely requires matching a specific street feature, so I’m prioritizing visual confirmation over broad regional clues.

Narrowed Canberra locations

{"system1_search_query":[{"q":"site:github.com "members.cssa.club""},{"q":"site:github.com/anucssa membership card"},{"q":"site:github.com "ANU CSSA" "membership card""},{"q":""CSSA membership card" ANU"}],"response_length":"long"}

Searched 16 websites

bash -lc env | grep -i proxy || true; getent hosts members.cssa.club || true; curl -I --max-time 10 https://members.cssa.club/ 2>&1 | head -30

Tested network access and proxy configuration

{"image_query":[{"q":"ANU CSSA membership card 2026"},{"q":"ANU Computer Science Students Association membership card"}],"response_length":"long"}

Searching the web

{"open":[{"ref_id":"https://maps.google.com"},{"ref_id":"https://maps.google.com/cbk?output=json&ll=-35.323439,149.134187"},{"ref_id":"https://maps.google.com/cbk?output=xml&ll=-35.323439,149.134187"}],"response_length":"long"}

Searched 1 website

bash -lc curl -vkI --max-time 15 --resolve members.cssa.club:443:150.203.186.188 https://members.cssa.club/ 2>&1 | head -80

Tested HTTPS access and queried DNS-over-HTTPS A records

{"system1_search_query":[{"q":"site:crt.sh cssa.club members"},{"q":""members.cssa.club" certificate"},{"q":""bushbash.cssa.club" certificate"},{"q":""cssa.club" "members" "bushbash""}],"response_length":"long"}

Searched 12 websites

{"open":[{"ref_id":"https://github.com/anucssa/noCTF-bushbash/archive/refs/heads/master.zip"}],"response_length":"short"}

Searching the web

{"system1_search_query":[{"q":"https://codeload.github.com/anucssa/noCTF-bushbash/zip/refs/heads/master"}],"response_length":"short"}

Searched 3 websites

bash -lc getent ahostsv4 bushbash.cssa.club || true; getent ahostsv4 github.com || true; cat /etc/resolv.conf

Checked DNS connectivity and analyzed the image

{"system1_search_query":[{"q":""bushbash.cssa.club" GitHub"},{"q":""api.bushbash.cssa.club""},{"q":""bushbash" "VITE_API_BASE_URL""},{"q":""BushBash" kubernetes CSSA GitHub"}],"response_length":"long"}

Searched 9 websites

{"system1_search_query":[{"q":"repo:anucssa/noCTF-bushbash "bushbash.cssa.club""},{"q":"repo:anucssa/noCTF-bushbash "API_BASE_URL""},{"q":"repo:anucssa/noCTF-bushbash "membership perks""},{"q":"repo:anucssa/noCTF-bushbash "Hackerman III""}],"response_length":"long"}

Searched 25 websites

bash -lc env | grep -i proxy || true; cat /etc/resolv.conf; curl -I --max-time 10 https://bushbash.cssa.club/ 2>&1 | head -30

Tested network connectivity and analyzed image access via proxy settings

{"system1_search_query":[{"q":""The CSSA Hackerman I""},{"q":""The CSSA Hackerman II""},{"q":""The CSSA Hackerman III""},{"q":""CSSA Hackerman" BushBash"}],"response_length":"long"}

Searched 15 websites

Worked for 37m 46s

回答

Mình chưa xác minh được hai flag tới mức có thể khẳng định mà không bịa.

Điểm đã xác nhận:

  • API công khai của giải là https://bushbash.cssa.club/api. (GitHub)
  • Ảnh Hackerman III không có GPS trong EXIF; dấu thời gian là giá trị mặc định của máy Panasonic NV-DS38, nên không thể lấy tọa độ trực tiếp từ metadata.
  • Khung cảnh nhiều khả năng thuộc khu nội đô Canberra, nhưng chưa đủ căn cứ để chốt tọa độ chính xác bốn chữ số thập phân.
  • Với membership perks, dữ kiện hiện có chỉ xác nhận thẻ thành viên phải được nhận thông qua quy trình đăng ký CSSA; chưa tìm thấy phần dữ liệu công khai cần ghép bằng dấu gạch ngang.

Vì yêu cầu của bạn là không bịa flag, mình không đưa ra đáp án phỏng đoán.

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