Malicious PDF — malware analysis report

Static analysis result for SHA-256 df897acc73811824…

MALICIOUS

PDF

45.5 KB Created: 2021-05-14 02:33:22 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-08-25
MD5: 1491efa35f79127953e088e043e1693a SHA-1: c852515e24aad9f07af6055c0e93e104ed929eae SHA-256: df897acc73811824499d1c193afe4bd2755ca3f5915ea231906733744892d7c9
260 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF document contains numerous links to external websites, many of which are part of a link farm designed to appear as search results for game hacks and free currency. One critical heuristic identified a link to a known malicious redirector infrastructure. The document body, though partially corrupted, contains text related to 'Free Robux Download' and includes URLs that are likely part of a lure to trick users into clicking through to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9507

Heuristics 6

  • 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.
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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.xyz/app/431946152/free-robux-download-game-hack In PDF document text
    • http://spentulib.com/search//repository/how-to-hack-and-get-free-robux_GM431946152.pdfIn PDF document text
    • http://spentulib.com/search/repository/minecraft-auto-miner-hack_GM479516143.pdfIn PDF document text
    • http://spentulib.com/search/repository/how-to-hack-roblox-to-get-free-robux_GM431946152.pdfIn PDF document text
    • http://spentulib.com/search/repository/free-robux-games-on-roblox_GM431946152.pdfIn PDF document text
    • http://spentulib.com/search/repository/coin-master-free-spins-hack_GM406889139.pdfIn PDF document text
    • http://spentulib.com/search//repository/easy-robux-hack_GM431946152.pdfIn PDF document text
    • http://spentulib.com/search/repository/spins-coin-master_GM406889139.pdfIn PDF document text
    • http://spentulib.com/search//repository/free-robux-websites-that-actually-work-2021_GM431946152.pdfIn PDF document text
    • http://spentulib.com/search//repository/how-to-hack-roblox-to-get-robux_GM431946152.pdfIn PDF document text
    • http://spentulib.com/search/repository/coin-master-free-spin-and-coin-link-today_GM406889139.pdfIn PDF document text
    • http://spentulib.com/search//repository/free-robux-hack-no-human-verification-or-survey_GM431946152.pdfIn PDF document text
    • http://spentulib.com/search//repository/how-to-buy-robux-for-free_GM431946152.pdfIn PDF document text
    • http://spentulib.com/search/repository/coin-master-hack-app-for-iphone_GM406889139.pdfIn PDF document text
    • http://spentulib.com/search/repository/coin-master-free-cards-and-spin-link_GM406889139.pdfIn PDF document text
    • http://spentulib.com/search//repository/free-spins-for-coin-master-game_GM406889139.pdfIn PDF document text
    • http://spentulib.com/search/repository/roblox-free-robux-generator_GM431946152.pdfIn PDF document text
    • http://spentulib.com/search//repository/free-robux-generator-com-roblox-hack_GM431946152.pdfIn PDF document text
    • http://spentulib.com/search/repository/how-do-i-get-free-robux-on-roblox_GM431946152.pdfIn PDF document text
    • http://spentulib.com/search//repository/play-minecraft-free-online-no-download_GM479516143.pdfIn PDF document text
    • http://spentulib.com/search//repository/roblox-hack-me-robux_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_off000045f4.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x45F4 26820 bytes
SHA-256: 27938f78a6ef3afc25c6ef2b58c128d7572c9a90355d0ddf4aac17db4748b922
font_01_sfnt_off000083d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x83D8 2844 bytes
SHA-256: baad2f3f6808f4af03fa9398e38c580c8d846f7f773a947d8cc1f39b2753d31a
font_02_sfnt_off00008d9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8D9A 18824 bytes
SHA-256: 8406cb1c38774726d91b6a9fb5333918f35ff34bd7dcb56cd5a50b6af28a82ee