Malicious PDF — malware analysis report

Static analysis result for SHA-256 826b0a8e5a25a056…

MALICIOUS

PDF

81.1 KB Created: 2021-09-15 13:00:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 6105d20c1936528af6d7ee204de3a332 SHA-1: 9940ab78179b719ab06f20af0d395890f23ca22f SHA-256: 826b0a8e5a25a056fb5d412dca6ded8d1efc3d6759b057e8b7be261e5b23733b
112 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and multiple external links, some pointing to compromised CMS upload directories and others part of a link farm. The presence of a 'download button' heuristic suggests a lure to download further malicious content. The ML classifier strongly indicates maliciousness, supporting the interpretation that this PDF is designed to exploit vulnerabilities or trick users into downloading malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 7

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • 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://crewmak.ru/uplcv?utm_term=super+mario+ppsspp+iso+download PDF link annotation
    • http://dieterheich.de/images/uploads/file/nuxujelezitozadibukisowu.pdfIn PDF document text
    • http://fcv-bo.org/data/fcv-bo/userfiles/file/50285022296.pdfIn PDF document text
    • http://furkansigorta.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/161382760c8e43---dexusegegumujepudivolop.pdfIn PDF document text
    • https://cam-ceeds.org/ckfinder/userfiles/files/73452520945.pdfIn PDF document text
    • https://maffart-guy.com/userfiles/file/23996065799.pdfIn PDF document text
    • http://prota.ru/upload/files/vamagiku.pdfIn PDF document text
    • https://basundharamart.com/userfiles/file/28542447877.pdfIn PDF document text
    • http://op-gold.com/ck_image/files/duvekofibikofodamiripupus.pdfIn PDF document text
    • http://evevoyance.fr/adh/.-/file/5986956769.pdfIn PDF document text
    • http://emrc.ie/upload/imagecontent/file/71660414486.pdfIn PDF document text
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138a3ee0d2e5---14809836477.pdfIn PDF document text
    • http://architettobotteonpierpaolostudioabacus.it/userfiles/files/43191702891.pdfIn PDF document text
    • http://penzionriverside.cz/files/file/rijusuzunojedabexigivifam.pdfIn PDF document text
    • http://schodylux.pl/userfiles/file/pojitu.pdfIn PDF document text
    • https://bistro-8.com/wp-content/plugins/super-forms/uploads/php/files/8c4cbc969ecd967d9ebaf7218c276fd2/gakukukenopopuja.pdfIn PDF document text
    • https://sunarchegypt.com/userfiles/file/49929384568.pdfIn PDF document text
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/1613a7ea0ec22c---konokavevasejajekejoxatut.pdfIn PDF document text
    • http://nikolalepojevic5.com/multimedia/file/bunovilijabesopemavukotu.pdfIn PDF document text
    • https://zerling.eu/nico/images/files/27456351247.pdfIn PDF document text
    • http://studioarchterreni.it/userfiles/files/jelokikoxibitesetav.pdfIn PDF document text
    • http://www.texaco.bargiel.com.pl/ckfinder/userfiles/files/zodonawidit.pdfIn PDF document text
    • http://flapboxes.com/userfiles/files/47008929959.pdfIn PDF document text
    • http://cps-mbstu.edu.bd/app/webroot/js/ckfinder/userfiles/files/39592469230.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d7de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7DE 17868 bytes
SHA-256: 1f2771e37e30cd61acac7f92aea09bfab677b72e543f660069d94d79fcafa371
font_01_sfnt_off00010615.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10615 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011e2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E2C 10716 bytes
SHA-256: 859eeb9f17e9f6ca0b3fec227c9447d58221b3ef6c35cc3f7faab3fe2364eebf

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