Malicious PDF — malware analysis report

Static analysis result for SHA-256 b2d937a3e1c8f725…

MALICIOUS

PDF

48.6 KB Created: 2021-06-09 14:38:46 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-09-16
MD5: 391c1b08cd85847f48e2c050e2fdb8e2 SHA-1: 1c91071f0fd1a59c145adcb666ff31de854931f5 SHA-256: b2d937a3e1c8f7252fc30a27f7d3066fcac84c1ddf25d00b6193203bcf0b128c
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains embedded links that lead to known malicious redirectors, specifically advertising free game hacks and currency. The primary link directs users to 'netcdn.tw', which is flagged as malicious infrastructure. While no scripts were explicitly extracted, the PDF structure and heuristic firings strongly indicate a social engineering lure designed to redirect users to potentially harmful content or further malicious downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9796

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.tw/app/431946152/elite-hacks-robux-game-hack In PDF document text
    • https://thoisuviet.vn/public/ckfinder/userfiles/files/free-tiktok-followers-and-likes_GM835599320.pdfIn PDF document text
    • https://thoisuviet.vn/public/ckfinder/userfiles/files/get-free-spins-link-in-coin-master_GM406889139.pdfIn PDF document text
    • https://thoisuviet.vn/public/ckfinder/userfiles/files/free-roblox-hack-us_GM431946152.pdfIn PDF document text
    • https://thoisuviet.vn/public/ckfinder/userfiles/files/free-unlimited-robux_GM431946152.pdfIn PDF document text
    • https://thoisuviet.vn/public/ckfinder/userfiles/files/is-minecraft-free_GM479516143.pdfIn PDF document text
    • https://thoisuviet.vn/public/ckfinder/userfiles/files/free-online-spins-coin-master_GM406889139.pdfIn PDF document text
    • https://thoisuviet.vn/public/ckfinder/userfiles/files/roblox-svg-free_GM431946152.pdfIn PDF document text
    • https://thoisuviet.vn/public/ckfinder/userfiles/files/roblox-2021-hack_GM431946152.pdfIn PDF document text
    • https://thoisuviet.vn/public/ckfinder/userfiles/files/free-spins-on-coin-master_GM406889139.pdfIn PDF document text
    • https://thoisuviet.vn/public/ckfinder/userfiles/files/cool-free-minecraft-skins_GM479516143.pdfIn PDF document text
    • https://thoisuviet.vn/public/ckfinder/userfiles/files/minecraft-free-install_GM479516143.pdfIn PDF document text
    • https://thoisuviet.vn/public/ckfinder/userfiles/files/hacks-minecraft_GM479516143.pdfIn PDF document text
    • https://thoisuviet.vn/public/ckfinder/userfiles/files/script-executor-roblox-free_GM431946152.pdfIn PDF document text
    • https://thoisuviet.vn/public/ckfinder/userfiles/files/how-to-get-minecraft-java-free_GM479516143.pdfIn PDF document text
    • https://thoisuviet.vn/public/ckfinder/userfiles/files/how-to-earn-robux-for-free-2021_GM431946152.pdfIn PDF document text
    • https://thoisuviet.vn/public/ckfinder/userfiles/files/free-minecraft-mods-for-pc_GM479516143.pdfIn PDF document text
    • https://thoisuviet.vn/public/ckfinder/userfiles/files/daily-free-spins-on-coin-master_GM406889139.pdfIn PDF document text
    • https://thoisuviet.vn/public/ckfinder/userfiles/files/easy-ways-to-get-free-robux_GM431946152.pdfIn PDF document text
    • https://thoisuviet.vn/public/ckfinder/userfiles/files/coin-master-hack-download-2021_GM406889139.pdfIn PDF document text
    • https://thoisuviet.vn/public/ckfinder/userfiles/files/coin-master-gold-cards-hack_GM406889139.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_004_off000053d5.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x53D5 25068 bytes
SHA-256: 8934361905ea76d728a7b0c9eafbc166a32a75dc5b3f80d2857cac76380508a9
font_01_sfnt_off00008db6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8DB6 3884 bytes
SHA-256: 40b61f8938bd710dc29dc58ba3fde91c245a6a69596ec569b4d27c769ca417cf
font_02_sfnt_off00009a5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x9A5E 18544 bytes
SHA-256: ac6375cab3083958b4f51f8c204ecfa322e6d230658898ac944057187a62cfca