Malicious PDF — malware analysis report

Static analysis result for SHA-256 bc1cecff0c81301d…

MALICIOUS

PDF

48.3 KB Created: 2021-06-03 06:07:07 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 305e5dd97ed44896c41527ac9321d7b9 SHA-1: 4022d37d54872e91c1652e38f406aea0f4eb9b85 SHA-256: bc1cecff0c81301ddf591db6fc2b4301ea23a4b2b087062b659a2aced138c7bc
280 Risk Score

Malware Insights

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

This PDF document contains multiple links designed to lure users into clicking on a "free generator / game hack" which redirects to a credential phishing page impersonating Facebook. The document also contains numerous links to other PDF files, suggesting a link farm or SEO poisoning attempt. The ML classifier strongly flagged this PDF as malicious, and the presence of redirector links and brand impersonation further supports a phishing attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9796

Heuristics 7

  • 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.
  • 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.online/app/431946152/free-robux-no-verification-game-hack.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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.online/app/431946152/free-robux-no-verification-game-hack In PDF document text
    • http://library.smpn2-byl.sch.id//repository/roblox-place-rewards_GM431946152.pdfIn PDF document text
    • http://library.smpn2-byl.sch.id//repository/how-to-earn-free-robux_GM431946152.pdfIn PDF document text
    • http://library.smpn2-byl.sch.id//repository/coin-master-hack-apk-ios_GM406889139.pdfIn PDF document text
    • http://library.smpn2-byl.sch.id//repository/free-robux-codes-2021-not-used_GM431946152.pdfIn PDF document text
    • http://library.smpn2-byl.sch.id//repository/coin-master-hack-mobile_GM406889139.pdfIn PDF document text
    • http://library.smpn2-byl.sch.id//repository/coin-master-free-spins-blogspot_GM406889139.pdfIn PDF document text
    • http://library.smpn2-byl.sch.id//repository/free-robux-redeem-codes-2021_GM431946152.pdfIn PDF document text
    • http://library.smpn2-byl.sch.id//repository/coin-master-free-coins-and-spins_GM406889139.pdfIn PDF document text
    • http://library.smpn2-byl.sch.id//repository/how-do-u-get-free-robux_GM431946152.pdfIn PDF document text
    • http://library.smpn2-byl.sch.id//repository/coin-master-free-spin-and-coin-link-haktuts-hacking-news_GM406889139.pdfIn PDF document text
    • http://library.smpn2-byl.sch.id//repository/download-hack-coin-master-apk_GM406889139.pdfIn PDF document text
    • http://library.smpn2-byl.sch.id//repository/coin-master-unlimited-free-spins-link-2021_GM406889139.pdfIn PDF document text
    • http://library.smpn2-byl.sch.id/repository/how-to-got-free-item-robux_GM431946152.pdfIn PDF document text
    • http://library.smpn2-byl.sch.id//repository/coin-master-hacks-for-free-spins_GM406889139.pdfIn PDF document text
    • http://library.smpn2-byl.sch.id//repository/apk-hack-coin-master_GM406889139.pdfIn PDF document text
    • http://library.smpn2-byl.sch.id//repository/john-doe-roblox-hacker_GM431946152.pdfIn PDF document text
    • http://library.smpn2-byl.sch.id//repository/do-you-get-windows-10-minecraft-for-free-with-java_GM479516143.pdfIn PDF document text
    • http://library.smpn2-byl.sch.id//repository/getrobux-ninja_GM431946152.pdfIn PDF document text
    • http://library.smpn2-byl.sch.id//repository/robux-free-c_GM431946152.pdfIn PDF document text
    • http://library.smpn2-byl.sch.id//repository/free-minecraft-mods-for-ps4_GM479516143.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
font_00_sfnt_off000053d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x53D2 25804 bytes
SHA-256: 499c8aeb98b80eae271e55e4459e5e55471af4c5b6d654b52c43f4dd6fb763c6
font_01_sfnt_off00008f3a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8F3A 2888 bytes
SHA-256: cea35febb52dd848fda636d3c9a00307dd81488221075bf65b1d268d3ae12741
font_02_sfnt_off00009938.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x9938 18600 bytes
SHA-256: 361892a278de990f6dfe9fe9f512a0ec39aeba1740037781b92f32c6ad2b5051