Malicious PDF — malware analysis report

Static analysis result for SHA-256 27c923b1d7f2b5b2…

MALICIOUS

PDF

44.5 KB Created: 2021-06-08 22:57:44 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-08-25
MD5: c76e48bf489ddd475b017cfcb5f45435 SHA-1: 93d65ccdf05d61ce3c1bda22f57f7d6db2cd90d9 SHA-256: 27c923b1d7f2b5b2f42617e175cb4a91e88e3ae8618741eb31ff47bb0e7248cc
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple links to known malicious redirectors, specifically advertising game hacks and generators. The primary lure URL, https://netcdn.tw/app/431946152/roblox-tk-hack-game-hack, is associated with a critical heuristic firing for malicious redirector links. The document body, though heavily obfuscated, contains references to game hacks and the same URL, reinforcing the lure. No scripts were extracted, but the presence of multiple malicious links indicates a phishing or scam attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9813

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/roblox-tk-hack-game-hack In PDF document text
    • http://unilin21.ru/images/moonactive-coin-master-hack_GM406889139.pdfIn PDF document text
    • http://unilin21.ru/images/free-spin-coin-master-new-link_GM406889139.pdfIn PDF document text
    • http://unilin21.ru/images/minecraft-items_GM479516143.pdfIn PDF document text
    • http://unilin21.ru/images/freespinandcoin-blogspot-coin-master_GM406889139.pdfIn PDF document text
    • http://unilin21.ru/images/free-robux-download_GM431946152.pdfIn PDF document text
    • http://unilin21.ru/images/coin-master-free-daily-spins_GM406889139.pdfIn PDF document text
    • http://unilin21.ru/images/free-modded-minecraft-server_GM479516143.pdfIn PDF document text
    • http://unilin21.ru/images/games-on-roblox-where-you-win-a-free-rixe_GM431946152.pdfIn PDF document text
    • http://unilin21.ru/images/robux-website_GM431946152.pdfIn PDF document text
    • http://unilin21.ru/images/roblox-land-free-robux_GM431946152.pdfIn PDF document text
    • http://unilin21.ru/images/how-to-become-a-hacker-in-roblox_GM431946152.pdfIn PDF document text
    • http://unilin21.ru/images/i-didnt-get-my-free-spins-in-coin-master_GM406889139.pdfIn PDF document text
    • http://unilin21.ru/images/coin-master-hack-without-verification_GM406889139.pdfIn PDF document text
    • http://unilin21.ru/images/rbxfree-com-free-robux_GM431946152.pdfIn PDF document text
    • http://unilin21.ru/images/tiktok-views-free_GM835599320.pdfIn PDF document text
    • http://unilin21.ru/images/free-spins-coin-master-app_GM406889139.pdfIn PDF document text
    • http://unilin21.ru/images/free-mod-apk-coin-master_GM406889139.pdfIn PDF document text
    • http://unilin21.ru/images/free-robux-instantly-no-survey_GM431946152.pdfIn PDF document text
    • http://unilin21.ru/images/coin-master-free-spins-today-daily-links_GM406889139.pdfIn PDF document text
    • http://unilin21.ru/images/free-spin-hack-coin-master-2021_GM406889139.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_off00004f54.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x4F54 25288 bytes
SHA-256: 4bb30e21b5caa9c4c680a76a5a4acabe1457153586efb04b3904473a0d83b6db
font_01_sfnt_off00008991.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8991 18836 bytes
SHA-256: 690fb3f2543bc114ee7ef9662e0b7f99061346f27f3585f03c6f04d2fd27576a