Malicious PDF — malware analysis report

Static analysis result for SHA-256 8df78b15fd962b4b…

MALICIOUS

PDF

48.4 KB Created: 2021-06-07 10:27:52 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-10-05
MD5: ed8e4cf2d873e1f8e5c9ea9d92521762 SHA-1: ae14ebf71677ffed81ae3d44e9206ba15490e687 SHA-256: 8df78b15fd962b4b500832901937d99ea8ffd998ff4e4881c4db02f4af79aff9
182 Risk Score

Malware Insights

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

The PDF contains numerous links to game hacks and generators, impersonating brands like PayPal to trick users into clicking. The ML classifier strongly flagged this PDF as malicious, and the presence of multiple external links suggests a link farm or redirection scheme. While no scripts were explicitly extracted, the PDF structure and heuristics indicate a lure for potentially malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9796

Heuristics 6

  • 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.
  • PDF links to a 'free generator / game hack' redirector high 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.
  • 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: https://netcdn.tw/app/431946152/roblox-guest-play-for-free-game-hack.
  • 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
  • External URI info PDF_URI
    PDF contains an external URL action
  • 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-guest-play-for-free-game-hack PDF link annotation
    • https://unsla.uns.ac.id:443/pgsd/repository/coin-master-cheats_GM406889139.pdfIn PDF document text
    • https://unsla.uns.ac.id:443/pgsd/repository/free-coins-and-free-spins-coin-master-2021_GM406889139.pdfIn PDF document text
    • https://unsla.uns.ac.id:443/pgsd/repository/robux-games_GM431946152.pdfIn PDF document text
    • https://unsla.uns.ac.id:443/pgsd/repository/coin-master-code-for-free-spins_GM406889139.pdfIn PDF document text
    • https://unsla.uns.ac.id:443/pgsd/repository/pokemon-go-free-verizon-code_GM1094591345.pdfIn PDF document text
    • https://unsla.uns.ac.id:443/pgsd/repository/grab-points-login_GM431946152.pdfIn PDF document text
    • https://unsla.uns.ac.id:443/pgsd/repository/coin-master-free-gift-links-2021_GM406889139.pdfIn PDF document text
    • https://unsla.uns.ac.id:443/pgsd/repository/get-free-spins-coin-master-link_GM406889139.pdfIn PDF document text
    • https://unsla.uns.ac.id:443/pgsd/repository/coin-master-35-13-hack-download_GM406889139.pdfIn PDF document text
    • https://unsla.uns.ac.id:443/pgsd/repository/robloxfun-com-robux_GM431946152.pdfIn PDF document text
    • https://unsla.uns.ac.id:443/pgsd/repository/www-roblox-com-robux-free_GM431946152.pdfIn PDF document text
    • https://unsla.uns.ac.id:443/pgsd/repository/how-to-get-roblox-premium-for-free-2021_GM431946152.pdfIn PDF document text
    • https://unsla.uns.ac.id:443/pgsd/repository/2021-free-spins-coin-master-link_GM406889139.pdfIn PDF document text
    • https://unsla.uns.ac.id:443/pgsd/repository/what-is-a-minecraft-client_GM479516143.pdfIn PDF document text
    • https://unsla.uns.ac.id:443/pgsd/repository/how-to-get-a-refund-on-roblox-2021_GM431946152.pdfIn PDF document text
    • https://unsla.uns.ac.id:443/pgsd/repository/free-robux-websites-that-actually-work-2021_GM431946152.pdfIn PDF document text
    • https://unsla.uns.ac.id:443/pgsd/repository/coin-master-hack-ios-download_GM406889139.pdfIn PDF document text
    • https://unsla.uns.ac.id:443/pgsd/repository/how-to-get-roblox-credit-for-free_GM431946152.pdfIn PDF document text
    • https://unsla.uns.ac.id:443/pgsd/repository/coin-master-hack-apk-android_GM406889139.pdfIn PDF document text
    • https://unsla.uns.ac.id:443/pgsd/repository/how-to-hack-someone-on-roblox_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_004_off00005355.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x5355 25152 bytes
SHA-256: 5b13be5f6afb50d890a39df9b21a78aa9be1839eed57423067ed03a7ddc11449
font_01_sfnt_off00008d6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8D6A 3500 bytes
SHA-256: e49a868379cd3c37e631c5a53c010e21f38d803532a2b8417aee82315d4e8634
font_02_sfnt_off0000990c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x990C 18756 bytes
SHA-256: c60aa395ff79e2f5a422b4fca90653bbbdc6c8c09e1a51c97170b9cbc69c5fc3

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