Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4e94813c2daf49c…

MALICIOUS

PDF

47.6 KB Created: 2021-06-11 08:58:28 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-10-11
MD5: bf00af492ed4b061e8b29d8a794ecbb5 SHA-1: 6252452560dbd397dc6fc11321b8d7faabacea12 SHA-256: a4e94813c2daf49cbaa224a365c0a0bbeb9d603b5e080c0e3a5a864c9e003166
300 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link T1059.001 PowerShell

This PDF document employs a fake CAPTCHA and clipboard command execution lure to trick users into running commands, likely to download and execute a second-stage payload. The document contains a critical link to a known malicious redirector, https://netcdn.tw/app/431946152/roblox-hack-commands-list-game-hack, which is a strong indicator of malicious intent. The overall workflow suggests a phishing or scam attempt designed to compromise the user's system.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9832

Heuristics 7

  • 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.
  • Fake CAPTCHA with command-running instructions critical SE_FAKE_CAPTCHA_CLICKFIX
    Document combines fake CAPTCHA or human-verification language with instructions to paste or run a command — a high-confidence ClickFix pattern
  • Clipboard command execution lure high SE_CLIPBOARD_COMMAND_LURE
    Document tells the user to copy or paste clipboard content into Run, PowerShell, cmd, or another shell-like execution context
  • 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
  • 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-hack-commands-list-game-hack In PDF document text
    • https://www.tiancom.com.tw/upload/files/roblox-scam_GM431946152.pdfIn PDF document text
    • https://www.tiancom.com.tw/upload/files/free-gold-cards-coin-master_GM406889139.pdfIn PDF document text
    • https://www.tiancom.com.tw/upload/files/get-free-robux-2021_GM431946152.pdfIn PDF document text
    • https://www.tiancom.com.tw/upload/files/how-to-get-free-robux-gift-cards_GM431946152.pdfIn PDF document text
    • https://www.tiancom.com.tw/upload/files/coin-master-500-free-spins_GM406889139.pdfIn PDF document text
    • https://www.tiancom.com.tw/upload/files/free-robux-com_GM431946152.pdfIn PDF document text
    • https://www.tiancom.com.tw/upload/files/hacker-scp-roblox_GM431946152.pdfIn PDF document text
    • https://www.tiancom.com.tw/upload/files/rc8-roblox-hack_GM431946152.pdfIn PDF document text
    • https://www.tiancom.com.tw/upload/files/tiktok-likes-free-trial_GM835599320.pdfIn PDF document text
    • https://www.tiancom.com.tw/upload/files/coin-master-daily-gifts_GM406889139.pdfIn PDF document text
    • https://www.tiancom.com.tw/upload/files/how-to-get-gold-cards-on-coin-master-hack_GM406889139.pdfIn PDF document text
    • https://www.tiancom.com.tw/upload/files/is-roblox-studio-free_GM431946152.pdfIn PDF document text
    • https://www.tiancom.com.tw/upload/files/is-minecraft-bedrock-edition-free_GM479516143.pdfIn PDF document text
    • https://www.tiancom.com.tw/upload/files/free-robux-without-verification-or-survey_GM431946152.pdfIn PDF document text
    • https://www.tiancom.com.tw/upload/files/roblox-hacks-and-cheats_GM431946152.pdfIn PDF document text
    • https://www.tiancom.com.tw/upload/files/pokemon-go-free-walk_GM1094591345.pdfIn PDF document text
    • https://www.tiancom.com.tw/upload/files/you-promised-my-son-free-robux_GM431946152.pdfIn PDF document text
    • https://www.tiancom.com.tw/upload/files/pokemon-go-free-or-james_GM1094591345.pdfIn PDF document text
    • https://www.tiancom.com.tw/upload/files/free-spins-for-coin-master-ios_GM406889139.pdfIn PDF document text
    • https://www.tiancom.com.tw/upload/files/free-op-minecraft-servers_GM479516143.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_off000055d1.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x55D1 28244 bytes
SHA-256: 492837865da3401237882a67054d410f7d591723b88030563385a2e539afa3f3
font_01_sfnt_off000095fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x95FC 18840 bytes
SHA-256: 4e4e3c6090800ea4d72cc49610a7f5426d503755de7ca2a329af356e3358d7a8

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