Malicious PDF — malware analysis report

Static analysis result for SHA-256 c6f620598348c03f…

MALICIOUS

PDF

51.3 KB Created: 2021-06-11 04:20:00 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-10-05
MD5: d1c0af28cd6f9fd32088476fd8590b40 SHA-1: cf21762006a9d34c60024572674eaa98c1e269ce SHA-256: c6f620598348c03f45316e8dad3e94c70ca1e58a9c129141859a3834631c5bbe
182 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF document employs a fake CAPTCHA and download button lure to trick users into clicking malicious links. The document contains numerous external links, many pointing to other PDFs hosted on orbai.ai, suggesting a link farm or redirector strategy. The ML classifier also flagged this PDF as malicious, indicating a high likelihood of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9871

Heuristics 6

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • PDF links to a 'free generator / game hack' redirector high PDF_GAME_HACK_REDIRECT_LURE
    PDF's clickable action targets a redirector of the form /app/<id>/<slug>-game-hack — the landing-page shape of a large SEO 'free spins / generator / game hack' lure family that funnels victims through rotating disposable hosts to a malware/scam payload. The multi-link variants also trip ML/link-farm rules; this catches the single-link variants that otherwise score clean.
  • Fake CAPTCHA / human verification prompt high SE_FAKE_CAPTCHA
    Document displays a fake CAPTCHA or human-verification prompt — used to trick users into running commands or pressing keyboard shortcuts
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • External URI info PDF_URI
    PDF contains an external URL action
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://netcdn.tw/app/431946152/roblox-cheat-engine-bypass-2021-super-power-training-game-hack PDF link annotation
    • https://www.orbai.ai/uploaded_files/userfiles/files/coin-master-hack-without-human-verification-2021_GM406889139.pdfIn PDF document text
    • https://www.orbai.ai/uploaded_files/userfiles/files/roblox-free-clothes-girl_GM431946152.pdfIn PDF document text
    • https://www.orbai.ai/uploaded_files/userfiles/files/minecraft-bedrock-edition-download-pc-free_GM479516143.pdfIn PDF document text
    • https://www.orbai.ai/uploaded_files/userfiles/files/games-that-can-be-hacked_GM431946152.pdfIn PDF document text
    • https://www.orbai.ai/uploaded_files/userfiles/files/can-you-get-minecraft-windows-10-for-free_GM479516143.pdfIn PDF document text
    • https://www.orbai.ai/uploaded_files/userfiles/files/coin-master-working-hack_GM406889139.pdfIn PDF document text
    • https://www.orbai.ai/uploaded_files/userfiles/files/coin-master-free-coins-and-spins-daily_GM406889139.pdfIn PDF document text
    • https://www.orbai.ai/uploaded_files/userfiles/files/10-free-roblox-gears_GM431946152.pdfIn PDF document text
    • https://www.orbai.ai/uploaded_files/userfiles/files/free-minecraft-skins-pc_GM479516143.pdfIn PDF document text
    • https://www.orbai.ai/uploaded_files/userfiles/files/coin-master-gold-cards-hack_GM406889139.pdfIn PDF document text
    • https://www.orbai.ai/uploaded_files/userfiles/files/coin-master-free-cards-link-2021_GM406889139.pdfIn PDF document text
    • https://www.orbai.ai/uploaded_files/userfiles/files/how-to-get-roebucks-in-roblox_GM431946152.pdfIn PDF document text
    • https://www.orbai.ai/uploaded_files/userfiles/files/can-you-get-banned-for-hacking-in-roblox_GM431946152.pdfIn PDF document text
    • https://www.orbai.ai/uploaded_files/userfiles/files/can-you-get-robux-for-free_GM431946152.pdfIn PDF document text
    • https://www.orbai.ai/uploaded_files/userfiles/files/win-free-robux_GM431946152.pdfIn PDF document text
    • https://www.orbai.ai/uploaded_files/userfiles/files/coin-master-free-spins-and-coins-today-gift-reward_GM406889139.pdfIn PDF document text
    • https://www.orbai.ai/uploaded_files/userfiles/files/free-robux-without-human-verification-real_GM431946152.pdfIn PDF document text
    • https://www.orbai.ai/uploaded_files/userfiles/files/minecraft-font-free_GM479516143.pdfIn PDF document text
    • https://www.orbai.ai/uploaded_files/userfiles/files/free-robux-accounts_GM431946152.pdfIn PDF document text
    • https://www.orbai.ai/uploaded_files/userfiles/files/free-spins-and-coins-for-coin-master-game_GM406889139.pdfIn PDF document text
    • http://en.wikipedia.org/wiki/MIT_LicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off00005406.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x5406 35440 bytes
SHA-256: 5b8d3ee5e70c19ee04829ef6a9cbe132ad2216110f65ae8b31cc2d095cecb87b
font_01_sfnt_off0000a1b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xA1B0 19904 bytes
SHA-256: 3e4ef39e0eb938dad71a3b678021e74f3bfccbbd5d1a69938d0333d498ea515d