Malicious PDF — malware analysis report

Static analysis result for SHA-256 57f875c825f65e67…

MALICIOUS

PDF

94.6 KB Created: 2021-09-19 14:31:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: dd31c43f4d2624179e2731d6c7cfc0ed SHA-1: 0859c844f140708738505e97cd8d78477ef2744f SHA-256: 57f875c825f65e67f2c926560310546a7f3b9f3ca800d3443d0b8a444f675109
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs that function as a link farm, directing users to potentially malicious websites. Several heuristics indicate that these links are hosted on compromised CMS uploads or disposable domains, suggesting a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly support the malicious nature of this PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://philabc.ru/uplcv?utm_term=discuss+the+various+types+of+environment PDF link annotation
    • https://prestinireedcorp.com/userfiles/files/remegiwenazerezobub.pdfIn PDF document text
    • https://drddvichitra.com/userfiles/file/tubufumakadipurizenojuva.pdfIn PDF document text
    • http://demenagements-remond.fr/userfiles/file/20210906224509.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/juvisezadig.pdfIn PDF document text
    • https://belgradenightlife.info/wp-content/plugins/super-forms/uploads/php/files/khngqcgr0jdf0dnf52bqu31v35/wosuvakefabiwasokujuzike.pdfIn PDF document text
    • http://zhongjiukeji.com/upload_fck/file/2021-9-18/20210918060829775364.pdfIn PDF document text
    • http://longarmquiltacademy.com/fckeditor/userfiles/file/wivatafewaxomofarepamuras.pdfIn PDF document text
    • http://manu-transport.com/documents/file/25817845453.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c91a6a107d---49556355756.pdfIn PDF document text
    • http://capitaloffice.pl/fotki/file/wufud.pdfIn PDF document text
    • http://shceping.com/upFile/photos/2021-9/file/6140204703.pdfIn PDF document text
    • http://kuppersbusch.hu/userfiles/files/29579366973.pdfIn PDF document text
    • https://tutorbolivia.com/userfiles/file/62369350230.pdfIn PDF document text
    • http://kanalizace-ul.cz/userfiles/file/79383589496.pdfIn PDF document text
    • http://www.mmd.ntou.edu.tw/ckfinder/userfiles/files/puvazedujijekenenememuwo.pdfIn PDF document text
    • https://bloc-immo.com/images/13547899766.pdfIn PDF document text
    • https://autosaloncenter.com/uploads/files/95075956513.pdfIn PDF document text
    • https://vr-spagna-20.effievirtual.com/galeria/files/rurinewajod.pdfIn PDF document text
    • https://nslogisticservice.com/userfiles/files/guzijawumukokimo.pdfIn PDF document text
    • http://amongelite.com/ci/userfiles/files/42067085927.pdfIn PDF document text
    • https://pbanerjeeservices.4digitmagic.com/userfiles/file/17673948842.pdfIn PDF document text
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614123b4297d5---piboxeruf.pdfIn PDF document text
    • https://abzesolar.com/uploads/files/gajitevemenikadag.pdfIn PDF document text
    • https://ijieet.org/ckfinder/userfiles/files/86813430250.pdfIn PDF document text
    • http://swhwsolution.it/ckeditor-ckfinder-integration/uploads/files/70898623469.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_off00010b92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B92 10980 bytes
SHA-256: 090ece879d70ae3108b6f3bc2a80329eb937afe916818d72ed904b63fe2e4ea7
font_01_sfnt_off000124f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124F5 18164 bytes
SHA-256: 44d0946853a0c67fd47c6e3bad05499c8816ac8f7854d480d9a6a0868e2b3821
font_02_sfnt_off00015432.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15432 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1