Malicious PDF — malware analysis report

Static analysis result for SHA-256 39bfa5be1c7138bc…

MALICIOUS

PDF

46.3 KB Created: 2021-06-03 08:19:15 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2026-06-04
MD5: 49fd1ff52d347d27ad86c628ef3c48e0 SHA-1: 80aa2d1bbab24a87421d47c58400f45f9d4edb90 SHA-256: 39bfa5be1c7138bca304610337750bdc8c7b926c42d927093c93a46c27929182
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a critical heuristic firing for a malicious redirector link, specifically pointing to a 'free generator / game hack' lure. The embedded URL, https://netcdn.online/app/431946152/earnrobux-game-hack, is associated with malicious redirector infrastructure. The document body, though heavily obfuscated, contains text related to earning Robux and references the malicious URL, reinforcing the lure. While no scripts were explicitly extracted, the PDF structure itself contains links that are indicative of a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9832

Heuristics 4

  • PDF links to a 'free generator / game hack' redirector critical 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. CRITICAL on its own: the /app/<id>/<slug>-game-hack path shape is unambiguous scam infra, and the host rotates so a host-list match can't be relied on.
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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
  • 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.online/app/431946152/earnrobux-game-hack In PDF document text
    • https://www.letapbiosolutions.com/uploaded_files/userfiles/files/robux-free-gift-card_GM431946152.pdfIn PDF document text
    • https://www.letapbiosolutions.com/uploaded_files/userfiles/files/is-minecraft-realms-free_GM479516143.pdfIn PDF document text
    • https://www.letapbiosolutions.com/uploaded_files/userfiles/files/minecraft-free-download-chromebook_GM479516143.pdfIn PDF document text
    • https://www.letapbiosolutions.com/uploaded_files/userfiles/files/coinmaster-gps-user-review-coinmaster-coin-master-hack-pagedemo-index_GM406889139.pdfIn PDF document text
    • https://www.letapbiosolutions.com/uploaded_files/userfiles/files/microsoft-roblox-rewards_GM431946152.pdfIn PDF document text
    • https://www.letapbiosolutions.com/uploaded_files/userfiles/files/free-unlimited-robux-no-hack-or-servay_GM431946152.pdfIn PDF document text
    • https://www.letapbiosolutions.com/uploaded_files/userfiles/files/link-for-free-spins-on-coin-master_GM406889139.pdfIn PDF document text
    • https://www.letapbiosolutions.com/uploaded_files/userfiles/files/free-robux-codes-no-human-verification_GM431946152.pdfIn PDF document text
    • https://www.letapbiosolutions.com/uploaded_files/userfiles/files/get-free-robux-no-human-verification_GM431946152.pdfIn PDF document text
    • https://www.letapbiosolutions.com/uploaded_files/userfiles/files/coin-master-free-spins-iphone-2021_GM406889139.pdfIn PDF document text
    • https://www.letapbiosolutions.com/uploaded_files/userfiles/files/minecraft-svg-images-free_GM479516143.pdfIn PDF document text
    • https://www.letapbiosolutions.com/uploaded_files/userfiles/files/coin-master-free-spins-and-coins_GM406889139.pdfIn PDF document text
    • https://www.letapbiosolutions.com/uploaded_files/userfiles/files/how-to-hack-roblox-for-robux_GM431946152.pdfIn PDF document text
    • https://www.letapbiosolutions.com/uploaded_files/userfiles/files/coin-master-32-hack-apk-download_GM406889139.pdfIn PDF document text
    • https://www.letapbiosolutions.com/uploaded_files/userfiles/files/pasos-para-hackear-coins-master_GM406889139.pdfIn PDF document text
    • https://www.letapbiosolutions.com/uploaded_files/userfiles/files/get-free-coins-on-coin-master_GM406889139.pdfIn PDF document text
    • https://www.letapbiosolutions.com/uploaded_files/userfiles/files/free-robux-generator-2021-no-survey_GM431946152.pdfIn PDF document text
    • https://www.letapbiosolutions.com/uploaded_files/userfiles/files/robux-hack-2021_GM431946152.pdfIn PDF document text
    • https://www.letapbiosolutions.com/uploaded_files/userfiles/files/free-robux-generator-no-human-verification-or-survey-2021_GM431946152.pdfIn PDF document text
    • https://www.letapbiosolutions.com/uploaded_files/userfiles/files/coin-master-hack-2021-android_GM406889139.pdfIn PDF document text
    • https://robuxhaxs.comIn 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_off000054f7.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x54F7 27172 bytes
SHA-256: 38a0e8527384332f59210aae2ffa4ad921d956e5bf97230db89593e2f6494f15
font_01_sfnt_off0000931e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x931E 18076 bytes
SHA-256: 2721194a66b32dfdaea4e26ed0bd84b304de41eeda81871a4ffc347c5a8adb25