Malicious PDF — malware analysis report

Static analysis result for SHA-256 31e233796cc45d18…

MALICIOUS

PDF

36.3 KB Created: 2021-07-08 13:20:45 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-11-21
MD5: b5a06e78ff8f7a69f9174f16dec7fb83 SHA-1: 26dda079f63f733089ec81a1bee81e79121bf566 SHA-256: 31e233796cc45d18195335d1a94b43416837ad8318d23a0d2f367fd57f353c86
200 Risk Score

Malware Insights

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

The PDF document contains multiple links that impersonate Facebook and lure users with promises of free game currency or hacks. These links redirect to malicious infrastructure, indicating a credential phishing or malware distribution attempt. The ML classifier strongly flagged this PDF as malicious, supporting the observed redirection and lure tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 5

  • 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.
  • 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/431946152/free-robux-only-username-no-human-verification-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
  • 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/431946152/free-robux-only-username-no-human-verification-game-hack In PDF document text
    • http://ycstamping.com.tw/image/data/files/roblox-free-tony-stark-tshirt_GM431946152.pdfIn PDF document text
    • http://ycstamping.com.tw/image/data/files/how-to-get-free-coins-on-flip-master_GM406889139.pdfIn PDF document text
    • http://ycstamping.com.tw/image/data/files/roblox-studio-free_GM431946152.pdfIn PDF document text
    • http://ycstamping.com.tw/image/data/files/get-more-robux_GM431946152.pdfIn PDF document text
    • http://ycstamping.com.tw/image/data/files/coin-master-card-collection-link_GM406889139.pdfIn PDF document text
    • http://ycstamping.com.tw/image/data/files/roblox-holy-sword-cheats_GM431946152.pdfIn PDF document text
    • http://ycstamping.com.tw/image/data/files/how-to-get-free-mods-in-minecraft_GM479516143.pdfIn PDF document text
    • http://ycstamping.com.tw/image/data/files/claim-roblox_GM431946152.pdfIn PDF document text
    • http://ycstamping.com.tw/image/data/files/programa-para-hackear-usuuarios-de-roblox_GM431946152.pdfIn PDF document text
    • http://ycstamping.com.tw/image/data/files/free-spins-and-coins-blogspot-coin-master_GM406889139.pdfIn PDF document text
    • http://ycstamping.com.tw/image/data/files/free-robux-codes-2021_GM431946152.pdfIn PDF document text
    • http://ycstamping.com.tw/image/data/files/free-minecraft-server-hosting-24-7_GM479516143.pdfIn PDF document text
    • http://ycstamping.com.tw/image/data/files/how-to-hack-roblox-with-inspect-element-2021_GM431946152.pdfIn PDF document text
    • http://ycstamping.com.tw/image/data/files/robux-free-gift-card-org-hack_GM431946152.pdfIn PDF document text
    • http://ycstamping.com.tw/image/data/files/coin-master-free-spins-facebook_GM406889139.pdfIn PDF document text
    • http://ycstamping.com.tw/image/data/files/download-coin-master-hack-tool-v1-9_GM406889139.pdfIn PDF document text
    • http://ycstamping.com.tw/image/data/files/can-you-give-me-free-robux_GM431946152.pdfIn PDF document text
    • http://ycstamping.com.tw/image/data/files/roblox-free-dominus-hat_GM431946152.pdfIn PDF document text
    • http://ycstamping.com.tw/image/data/files/ss-by-snape-2021-hack-roblox_GM431946152.pdfIn PDF document text
    • http://ycstamping.com.tw/image/data/files/coin-master-game-hunters-club_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
font_00_sfnt_off00003465.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x3465 22668 bytes
SHA-256: 69afb9371eb429a4f006768df31694739a4ca432c4ffcd06be4bd32ce20dff86
font_01_sfnt_off0000674f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x674F 19588 bytes
SHA-256: 2aa3163e32aa61887c262fca8289404382398ed533c0aa8410485c934e17860b

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