Malicious PDF — malware analysis report

Static analysis result for SHA-256 c57820817a56923e…

MALICIOUS

PDF

82.2 KB Created: 2021-10-04 21:53:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: d5cecf733943d60f517114508e97acb3 SHA-1: 586fe6418b700c8bd8d00f1ae7b698aff5b73325 SHA-256: c57820817a56923e2d5b1266de43665d0abfb0acf4e5dd6d35c5f5546d4cebbc
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, with heuristics indicating embedded JavaScript and a link farm pointing to compromised CMS uploads. The embedded JavaScript likely facilitates the redirection or execution of malicious content. The numerous URLs suggest an attempt to obscure the final destination and potentially distribute malware or conduct phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • 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://oniceh.ru/uplcv?utm_term=what+animals+live+in+the+amazon+forest PDF link annotation
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1614966ca8e110---69169636187.pdfIn PDF document text
    • http://career-id.org/ckfinder/userfiles/files/27914375509.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/0i5a81bvmug3sj0otob606sh5m/dusajuroviperu.pdfIn PDF document text
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/f0peqo6sf276i0ka09ehcjito6/podawijopidoxis.pdfIn PDF document text
    • https://lederstuehle-shop.de/ckfinder/userfiles/files/53025274256.pdfIn PDF document text
    • http://dkind.net/userData/board/file/gutabanufapenifitexevi.pdfIn PDF document text
    • http://gmtshipping.com/attachment/file/88920879288.pdfIn PDF document text
    • http://diagonal.org.ar/wp-content/plugins/formcraft/file-upload/server/content/files/1613fb6641efa1---zumof.pdfIn PDF document text
    • http://victorylimo1.com/wp-content/plugins/formcraft/file-upload/server/content/files/16159f6af7af9d---51501222465.pdfIn PDF document text
    • http://urotunisia.com/uploads/FCK_files/file/66949527684.pdfIn PDF document text
    • https://gtsk.solar-napkollektor.hu/js/ckfinder/userfiles/files/43550901975.pdfIn PDF document text
    • http://lucchetta.net/userfiles/files/60511478661.pdfIn PDF document text
    • https://www.le-domaine-de-hauterive.fr/ckfinder/userfiles/files/11972103843.pdfIn PDF document text
    • http://banner-ever.com/ckImg/files/58602269594.pdfIn PDF document text
    • https://perfumes.dropship-tracking.com/userfiles/files/25130853045.pdfIn PDF document text
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/0otv5igvrcudd6d2li3ga196k4/65180519001.pdfIn PDF document text
    • http://studioagronomoserragiotto.eu/userfiles/files/vefisikanovopirexareruge.pdfIn PDF document text
    • http://www.de.ruben.pl/ckfinder/userfiles/files/1142275932.pdfIn PDF document text
    • https://denis-lefebvre-services.com/fichiers/file/72712104151.pdfIn PDF document text
    • https://marblobath.marblobaths.ph/app/webroot/img/files/timuwolakegetilone.pdfIn PDF document text
    • http://xn--22cjbbm2eyae3ehabdb4kqdtae3dxnnc1fhf.com/user_img/files/91842921181.pdfIn PDF document text
    • http://hifitness.hu/userfiles/file/tovemunotunovebudijo.pdfIn PDF document text
    • http://accronline.com/userfiles/file/44140182757.pdfIn PDF document text
    • http://zuche0551.com/upload/file/19110876963.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_off0000d826.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD826 19488 bytes
SHA-256: aa7fcd123a4e8a7859a017b7f3cbfbf0ea585f867c379e1b8bfa8e3e23b95195
font_01_sfnt_off00010b10.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B10 10596 bytes
SHA-256: a5805f52643a461553c5dc0bbe627249e8e3ca305e1820e982acf81a58ab8cbb
font_02_sfnt_off0001231e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1231E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1