Malicious PDF — malware analysis report

Static analysis result for SHA-256 ab241afc257580eb…

MALICIOUS

PDF

80.4 KB Created: 2021-08-30 23:59:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 831aba62765814bc90c83aac582141d2 SHA-1: 436b73aceedb17f19d60e3b081c50d6fcb4529ef SHA-256: ab241afc257580ebd0e4b9805fb90516bf1c481237dfa9ac19a0509e0d038f53
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous external links, many pointing to compromised websites or disposable domains, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly support its malicious nature. The document body is heavily obfuscated and unreadable, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 6

  • 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.
  • 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://laborke.ru/uplcv?utm_term=types+of+real+numbers PDF link annotation
    • http://interno-kazan.ru/upload/files/suputerunusovinekifal.pdfIn PDF document text
    • https://anthonygillant.com/userfiles/file/bulawununol.pdfIn PDF document text
    • http://drivescuolaguida.it/userfiles/files/63034980809.pdfIn PDF document text
    • https://montpellier-business-plan.com/mbp/upload/images/images/upload/ckfinder/dokamavomuvojuxejilegig.pdfIn PDF document text
    • https://www.hermanosvalerorecio.com//ckfinder/userfiles/files/sajoribebi.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab26f491983---muxakilu.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/nsdvr813uu9nb50t4i33gs606h/31879757921.pdfIn PDF document text
    • http://www.adatechotomasyon.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b046c333c3f---lepetu.pdfIn PDF document text
    • https://gulfsupremesa.com/ckfinder/userfiles/files/vikasupajalapekotuguwifu.pdfIn PDF document text
    • http://wcsps.com.tw/ckfinder/userfiles/files/21937469844.pdfIn PDF document text
    • https://shian-jin.com/UserFiles/files/54843409081.pdfIn PDF document text
    • http://studioriboldi.eu/userfiles/files/wutanuluwirarakudin.pdfIn PDF document text
    • http://sunwisechem.com/Uploadfiles/files/63890240020.pdfIn PDF document text
    • http://englishkan.net/UserFiles/File/mekaju.pdfIn PDF document text
    • http://hijoin.hu/editor_up/94911324150.pdfIn PDF document text
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607cde9635385---xibizulaworavowo.pdfIn PDF document text
    • http://lhdrum.com/User_File/UpFile/file/20210603141015_NzgzNDkyOTYwMzY=.pdfIn PDF document text
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160746c55bd327---42049741334.pdfIn PDF document text
    • https://pezenasenchantee.fr/userfiles/file/37328954132.pdfIn PDF document text
    • https://renebeumer.nl/userfiles/file/45245454535.pdfIn PDF document text
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606d2524f369d---73895273359.pdfIn PDF document text
    • https://tucarrorentacar.co/ckfinder/userfiles/files/sopegaxonegizofupa.pdfIn PDF document text
    • http://duetsepolno.pl/userfiles/file/lodurexujubidod.pdfIn PDF document text
    • https://mimpiindah88.com/contents/files/tinefabufosup.pdfIn PDF document text
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/160a3439d79099---68176235376.pdfIn PDF document text
    • https://www.rogierstoel.nl/wp-content/plugins/super-forms/uploads/php/files/rtf1jnfrf7ucv8cgf19dnaifdd/nelazedomeli.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_off0000d412.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD412 10648 bytes
SHA-256: 6b5b189cba225d06217e91f96192a6ab9725ef40cc4d6d7ba5010b83539e63bf
font_01_sfnt_off0000ec3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC3D 18172 bytes
SHA-256: 16fd5f2034ca3cece5095c28e403a25c04829c952fee39cf4ab3dad0e1cba1db
font_02_sfnt_off00011ae5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AE5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1