Malicious PDF — malware analysis report

Static analysis result for SHA-256 efb93d486974605e…

MALICIOUS

PDF

49.4 KB Created: 2021-06-13 21:54:05 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-11-22
MD5: ba809e6f5069c5a259de63e94e95ea75 SHA-1: 9866e746cda684477b2435032f39967b880ad2f2 SHA-256: efb93d486974605ea5faa8504512770eacb5b21f6b5e7c6c79e10403d354978d
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 advertising a 'game hack' lure. The embedded URL, http://netcdn.co/app/431946152/roblox-cs-hack-game-hack, is also flagged as malicious. The document body, though heavily obfuscated, contains references to this URL and appears to be part of the lure. No scripts were extracted, but the overall pattern suggests a phishing attempt to redirect users to potentially malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9228

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 http://netcdn.co/app/431946152/roblox-cs-hack-game-hack In PDF document text
    • https://www.christchurch-burton.staffs.sch.uk/admin/ckfinder/userfiles/files/how-to-get-free-mods-in-minecraft_GM479516143.pdfIn PDF document text
    • https://www.christchurch-burton.staffs.sch.uk/admin/ckfinder/userfiles/files/free-minecraft-gift-card_GM479516143.pdfIn PDF document text
    • https://www.christchurch-burton.staffs.sch.uk/admin/ckfinder/userfiles/files/coin-master-free_GM406889139.pdfIn PDF document text
    • https://www.christchurch-burton.staffs.sch.uk/admin/ckfinder/userfiles/files/is-the-game-roblox-free_GM431946152.pdfIn PDF document text
    • https://www.christchurch-burton.staffs.sch.uk/admin/ckfinder/userfiles/files/roblox-hacked-version_GM431946152.pdfIn PDF document text
    • https://www.christchurch-burton.staffs.sch.uk/admin/ckfinder/userfiles/files/roblox-hack-2021-may_GM431946152.pdfIn PDF document text
    • https://www.christchurch-burton.staffs.sch.uk/admin/ckfinder/userfiles/files/free-roblox-hair-girl_GM431946152.pdfIn PDF document text
    • https://www.christchurch-burton.staffs.sch.uk/admin/ckfinder/userfiles/files/get-free-robux-today_GM431946152.pdfIn PDF document text
    • https://www.christchurch-burton.staffs.sch.uk/admin/ckfinder/userfiles/files/coin-master-hack-club_GM406889139.pdfIn PDF document text
    • https://www.christchurch-burton.staffs.sch.uk/admin/ckfinder/userfiles/files/coin-master-cheat-codes_GM406889139.pdfIn PDF document text
    • https://www.christchurch-burton.staffs.sch.uk/admin/ckfinder/userfiles/files/free-1-robux_GM431946152.pdfIn PDF document text
    • https://www.christchurch-burton.staffs.sch.uk/admin/ckfinder/userfiles/files/chisel-and-bits-mod-minecraft-pe_GM479516143.pdfIn PDF document text
    • https://www.christchurch-burton.staffs.sch.uk/admin/ckfinder/userfiles/files/can-you-get-robux-for-free_GM431946152.pdfIn PDF document text
    • https://www.christchurch-burton.staffs.sch.uk/admin/ckfinder/userfiles/files/coin-master-links-for-free-spins-2021_GM406889139.pdfIn PDF document text
    • https://www.christchurch-burton.staffs.sch.uk/admin/ckfinder/userfiles/files/minecraft-education-edition-free_GM479516143.pdfIn PDF document text
    • https://www.christchurch-burton.staffs.sch.uk/admin/ckfinder/userfiles/files/get-free-robux-info_GM431946152.pdfIn PDF document text
    • https://www.christchurch-burton.staffs.sch.uk/admin/ckfinder/userfiles/files/free-roblox-card_GM431946152.pdfIn PDF document text
    • https://www.christchurch-burton.staffs.sch.uk/admin/ckfinder/userfiles/files/coin-master-spin-cheat_GM406889139.pdfIn PDF document text
    • https://www.christchurch-burton.staffs.sch.uk/admin/ckfinder/userfiles/files/minecraft-116-apk-download_GM479516143.pdfIn PDF document text
    • https://www.christchurch-burton.staffs.sch.uk/admin/ckfinder/userfiles/files/how-to-get-free-robux-on-roblox-2021_GM431946152.pdfIn PDF document text
    • http://en.wikipedia.org/wiki/MIT_LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_003_off00004e44.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x4E44 30188 bytes
SHA-256: fb5fc85f92e17423908aaa088beceac7e95f2ab1fa6fdd4fa40d21f94fed9cf8
font_01_sfnt_off00009225.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x9225 3656 bytes
SHA-256: 63a179d8a9645bea05c6d53b1776faf4e4a7281930de6cf484e639846bec2e20
font_02_sfnt_off00009edf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x9EDF 18184 bytes
SHA-256: f3f7b3f49ebd65d54e573eea8504b4ccddb34aced4893e65b0b4e08b8b645312