Malicious PDF — malware analysis report

Static analysis result for SHA-256 b88ad86667c358d0…

MALICIOUS

PDF

48.0 KB Created: 2021-05-12 02:00:11 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-10-01
MD5: 33a71f7e7f1d82845be8137aa4c4a420 SHA-1: d28151ea3af21f35f3978c9259a861ac41ce73d4 SHA-256: b88ad86667c358d06654a8648d35923e8fd81d7c3f864fb8dc067f52bc7265f1
182 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by an ML classifier. It uses brand-impersonation credential phishing. The file embeds a large number of external links characteristic of an SEO link farm, routes users through malicious redirector infrastructure and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9013

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.xyz/app/431946152/free-robux-no-verification-at-all-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.xyz/app/431946152/free-robux-no-verification-at-all-game-hack PDF link annotation
    • http://elearning.mtsmatholiulhudabugel.com/__statics/gudangsoal/files/robux-only_GM431946152.pdfIn PDF document text
    • http://elearning.mtsmatholiulhudabugel.com/__statics/gudangsoal/files/how-to-get-free-robux-without-any-verification_GM431946152.pdfIn PDF document text
    • http://elearning.mtsmatholiulhudabugel.com/__statics/gudangsoal/files/http-appsmob-info-coin-master-hack_GM406889139.pdfIn PDF document text
    • http://elearning.mtsmatholiulhudabugel.com/__statics/gudangsoal/files/how-to-hack-a-roblox-account-2021_GM431946152.pdfIn PDF document text
    • http://elearning.mtsmatholiulhudabugel.com/__statics/gudangsoal/files/coin-master-hack-spins-android_GM406889139.pdfIn PDF document text
    • http://elearning.mtsmatholiulhudabugel.com/__statics/gudangsoal/files/coin-master-gold-cards-hack_GM406889139.pdfIn PDF document text
    • http://elearning.mtsmatholiulhudabugel.com/__statics/gudangsoal/files/spin-rewards-coin-master_GM406889139.pdfIn PDF document text
    • http://elearning.mtsmatholiulhudabugel.com/__statics/gudangsoal/files/coin-master-free-spins--coins-2021_GM406889139.pdfIn PDF document text
    • http://elearning.mtsmatholiulhudabugel.com/__statics/gudangsoal/files/noob-vs-pro-vs-hacker-vs-god-minecraft_GM479516143.pdfIn PDF document text
    • http://elearning.mtsmatholiulhudabugel.com/__statics/gudangsoal/files/coin-master-free-spins-ios-2021_GM406889139.pdfIn PDF document text
    • http://elearning.mtsmatholiulhudabugel.com/__statics/gudangsoal/files/free-robux-mobile_GM431946152.pdfIn PDF document text
    • http://elearning.mtsmatholiulhudabugel.com/__statics/gudangsoal/files/coin-master-daily-spin-link-app_GM406889139.pdfIn PDF document text
    • http://elearning.mtsmatholiulhudabugel.com/__statics/gudangsoal/files/free-robux-no-gift-card_GM431946152.pdfIn PDF document text
    • http://elearning.mtsmatholiulhudabugel.com/__statics/gudangsoal/files/what-is-coin-master-app_GM406889139.pdfIn PDF document text
    • http://elearning.mtsmatholiulhudabugel.com/__statics/gudangsoal/files/coin-master-free-spins-deutsch-download-2021-link_GM406889139.pdfIn PDF document text
    • http://elearning.mtsmatholiulhudabugel.com/__statics/gudangsoal/files/toolbox-for-mcpe_GM479516143.pdfIn PDF document text
    • http://elearning.mtsmatholiulhudabugel.com/__statics/gudangsoal/files/bux-free-robux_GM431946152.pdfIn PDF document text
    • http://elearning.mtsmatholiulhudabugel.com/__statics/gudangsoal/files/microsoft-bing-robux_GM431946152.pdfIn PDF document text
    • http://elearning.mtsmatholiulhudabugel.com/__statics/gudangsoal/files/free-spins-coin-master_GM406889139.pdfIn PDF document text
    • http://elearning.mtsmatholiulhudabugel.com/__statics/gudangsoal/files/roblox-hack-ga_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_off00004a6f.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x4A6F 28748 bytes
SHA-256: 39ecec6b70b36d77b3be45465469a9a6d07c53565baf17e26c12e89fa28a68e3
font_01_sfnt_off00008ae1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8AE1 5696 bytes
SHA-256: 450e3ee45915afe13702bf1d587eb8b9ad88a8d2113419ac9f2fd116a828e139
font_02_sfnt_off000097f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x97F2 18676 bytes
SHA-256: a2274236a7a2e18adabb7b86c58cf77696514c901240e043c32ff4f0260e6091