Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fa396cb37cc5ac8…

MALICIOUS

PDF

91.9 KB Created: 2021-08-05 08:04:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 4306670e1f8670916f5b783dff75a1fa SHA-1: 9f85b737f7c06cacc837cbe35a2c0ee8999081ec SHA-256: 4fa396cb37cc5ac85080d30993ea34774c31abc381db44b85515fa258cbda3c8
156 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Static analysis revealed it functions as a link farm, with numerous URLs pointing to compromised CMS upload directories, suggesting a phishing or malware distribution scheme. The presence of multiple distinct hosts and disposable hosting patterns further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607ea00a21c4a---23505437670.pdf In PDF document text
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1607db399ee4a1---91676494057.pdfIn PDF document text
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1606eaa1d79b3b---78101703951.pdfIn PDF document text
    • http://ibnuaffan.com/ckfinder/userfiles/files/41940995813.pdfIn PDF document text
    • https://lacecinella.com/writable/public/userfiles/file/tunizosibowifazodu.pdfIn PDF document text
    • https://1sis.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7a14f77669---felunubil.pdfIn PDF document text
    • http://hawks79.com/clients/85064/File/33183795451.pdfIn PDF document text
    • https://eyetracking.pl/userfiles/file/99395246070.pdfIn PDF document text
    • http://movietek.vn/hinh-anh/files/fasijivefutalodepinisadom.pdfIn PDF document text
    • http://111-orte.de/testarea/cwsCMSlight/media/files/43468316063.pdfIn PDF document text
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/dkjbnmechke9221e4a2eacgvfb/60797914880.pdfIn PDF document text
    • http://www.k-24.com/wp-content/plugins/formcraft/file-upload/server/content/files/160788320177b0---sirerajefur.pdfIn PDF document text
    • https://nowbali.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/16072151f3eee3---derikininawujatiwakaxaga.pdfIn PDF document text
    • http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/1607a43c1dff43---82481357426.pdfIn PDF document text
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/66c41b5f0f5afc55f0b4f6e19ba71ee1/32002628572.pdfIn PDF document text
    • http://traiteur-ribot.fr/userfiles/file/kogetezam.pdfIn PDF document text
    • https://dazzlin.co.uk/wp-content/plugins/super-forms/uploads/php/files/0cd38cddd04fbdf0548a7ae9f1dded22/buzaxixizotexofur.pdfIn PDF document text
    • https://diaochue.vn/userfiles/file/guvekos.pdfIn PDF document text
    • https://www.parkgest.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1609aaaa19e532---voranopizudijel.pdfIn PDF document text
    • http://mindentudor.hu/userfiles/file/66318200766.pdfIn PDF document text
    • http://clinicaveterinariamontecchia.com/userfiles/files/javazuzoxivugurafekavef.pdfIn PDF document text
    • http://kmkonsult.cz/userfiles/file/37879279255.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=what+happens+in+act+4+scene+3+of+julius+caesarPDF link annotation
    • 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_off00010538.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10538 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011d4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D4F 11052 bytes
SHA-256: bc330c7a07d46014cb7d80d8df47d968b5c7d77fd42914251442876cd4c190ca
font_02_sfnt_off00013700.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13700 16484 bytes
SHA-256: c04aba2abc532d140f6f79ef7ff80ad3fa6dd0b5c1efc073d60cdf295de26f93