Malicious PDF — malware analysis report

Static analysis result for SHA-256 85b918c6aeb195e5…

MALICIOUS

PDF

251.0 KB Created: 2021-07-10 02:07:34 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-08-25
MD5: 82e29e94f5f2930c4be23fbd1f55f316 SHA-1: 72e221c626484deecd6cd7b0a5818dd173a428e9 SHA-256: 85b918c6aeb195e546c97a0c2eee402623849d5812b302393f103a9e083e2329
258 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link T1055 Process Injection T1140 Deobfuscate/Decode Files or Information T1071.001 Web Protocols

The PDF document contains multiple links to malicious redirector infrastructure, specifically advertising a 'free generator / game hack'. The document body and heuristics indicate a lure for a fake CAPTCHA or MFA prompt, consistent with credential harvesting. The presence of embedded URLs and the nature of the lures suggest this file is part of a phishing campaign, likely delivered as an attachment.

Machine Learning

  • Nyx PDF Classifier clean score 0.0098

Heuristics 8

  • 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 / 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
  • MFA / one-time-code harvesting lure high SE_MFA_LURE
    Document asks for a one-time code, authenticator approval, or MFA confirmation — consistent with credential phishing kits that steal session tokens or abuse multi-factor authentication
  • Brand-impersonation credential phishing lure high SE_BRAND_CREDENTIAL_PHISH
    Document impersonates a well-known consumer brand and uses account-security / verification language ('unusual activity', 'account on hold', 'verify your account') to steer the reader to a credential-harvesting link. Corroborated by: call-to-action link host does not match the impersonated brand: http://netcdn.tw/app/1330123889/pubg-uc-free-redeem-code-game-hack.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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.tw/app/1330123889/pubg-uc-free-redeem-code-game-hack In PDF document text
    • https://www.vadai.sg/uploaded_files/userfiles/files/how-to-hack-roblox-robux-with-cheat-engine_GM431946152.pdfIn PDF document text
    • https://www.vadai.sg/uploaded_files/userfiles/files/how-to-hack-dayz-roblox_GM431946152.pdfIn PDF document text
    • https://www.vadai.sg/uploaded_files/userfiles/files/how-to-get-minecraft-for-free-on-xbox-360_GM479516143.pdfIn PDF document text
    • https://www.vadai.sg/uploaded_files/userfiles/files/how-to-get-free-gift-card-codes-roblox_GM431946152.pdfIn PDF document text
    • https://www.vadai.sg/uploaded_files/userfiles/files/minecraft-win-10-free_GM479516143.pdfIn PDF document text
    • https://www.vadai.sg/uploaded_files/userfiles/files/hack-coin-master-for-free_GM406889139.pdfIn PDF document text
    • https://www.vadai.sg/uploaded_files/userfiles/files/without-pokemon-go-free-evolve-after-trade_GM1094591345.pdfIn PDF document text
    • https://www.vadai.sg/uploaded_files/userfiles/files/free-robux-real-working_GM431946152.pdfIn PDF document text
    • https://www.vadai.sg/uploaded_files/userfiles/files/minecraft-on-computer-free_GM479516143.pdfIn PDF document text
    • https://www.vadai.sg/uploaded_files/userfiles/files/roblox-card-pin-hack_GM431946152.pdfIn PDF document text
    • https://www.vadai.sg/uploaded_files/userfiles/files/hack-robux_GM431946152.pdfIn PDF document text
    • https://www.vadai.sg/uploaded_files/userfiles/files/how-to-hack-dead-winter-roblox-mac-2021_GM431946152.pdfIn PDF document text
    • https://www.vadai.sg/uploaded_files/userfiles/files/coin-master-free-daily-spins_GM406889139.pdfIn PDF document text
    • https://www.vadai.sg/uploaded_files/userfiles/files/free-spin-coin_GM406889139.pdfIn PDF document text
    • https://www.vadai.sg/uploaded_files/userfiles/files/get-more-free-spins-on-coin-master_GM406889139.pdfIn PDF document text
    • https://www.vadai.sg/uploaded_files/userfiles/files/google-how-can-i-get-free-robux_GM431946152.pdfIn PDF document text
    • https://www.vadai.sg/uploaded_files/userfiles/files/is-roblox-free-on-nintendo-switch_GM431946152.pdfIn PDF document text
    • https://www.vadai.sg/uploaded_files/userfiles/files/roblox-rewards-robux_GM431946152.pdfIn PDF document text
    • https://www.vadai.sg/uploaded_files/userfiles/files/how-to-hack-other-peoples-inventory-in-roblox-adopt-me_GM431946152.pdfIn PDF document text
    • https://www.vadai.sg/uploaded_files/userfiles/files/free-money-links-coin-master_GM406889139.pdfIn PDF document text
    • http://en.wikipedia.org/wiki/MIT_LicenseIn PDF document text

Related samples 4

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_024_off00037e48.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x37E48 25928 bytes
SHA-256: 1f3d25140e754d81e6454932c1ab2c684a1fa7cfe7edc7da63da1368d4fefe84
font_01_sfnt_off0003bb5b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x3BB5B 18864 bytes
SHA-256: 3d7187f3d3a6a56316946150b9ed33d0daf026efe5316677497c448afecda822

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