Malicious PDF — malware analysis report

Static analysis result for SHA-256 d51b3871b1a09159…

MALICIOUS

PDF

86.7 KB Created: 2021-08-10 23:23:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 6b3797286da06d6365ec0e408a15d737 SHA-1: 18f9a0c3587d8b82e8d53ccbe49f92ea701b560d SHA-256: d51b3871b1a09159b7406c5b8081c6bcdd4c3d75d062476a306cb21de6bdf366
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple compromised WordPress upload directories and disposable hosting sites. While no scripts were explicitly extracted, the PDF structure and link farm behavior suggest an intent to redirect users to malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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 http://www.rec39.ru/wp-content/plugins/super-forms/uploads/php/files/f407cbb71a19f468f0e8bf31b3b99b81/ripaguxibu.pdf In PDF document text
    • http://axwelindia.com/uploads/35568255240.pdfIn PDF document text
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/fe69fb3c3dca71301df1a19a566d862f/zanepuxidezepokokorap.pdfIn PDF document text
    • https://aptitudeclass.com/ckfinder/userfiles/files/lovaxifijepebuxuto.pdfIn PDF document text
    • http://originalcheck.it/public/img_admin/file///53404944748.pdfIn PDF document text
    • http://vimbark.sk/editor_uploads/files/vibele.pdfIn PDF document text
    • https://sinaia-vik.com/admin/fckeditor/editor/filemanager/connectors/php/file/fepojodefef.pdfIn PDF document text
    • https://denizlihorozu.com/resimler/files/27951481590.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/9db8858ec8a57d5351f9dbf98815a6b2/94436740068.pdfIn PDF document text
    • http://www.orarestauratorisaf.it/wp-content/plugins/formcraft/file-upload/server/content/files/160f3430414ab4---59349665003.pdfIn PDF document text
    • https://synersys.fr/contenu/file/widup.pdfIn PDF document text
    • https://www.qbuildsoftware.com/wp-content/plugins/super-forms/uploads/php/files/56fd26a9ecb1f393385cfaea2d966442/gevas.pdfIn PDF document text
    • http://es-umzuege-transporte.de/wp-content/plugins/super-forms/uploads/php/files/10a686dc20f0166e4dd325aa5447ff0b/rogojelifazajo.pdfIn PDF document text
    • http://cecev.com/stockages/files/zobejazefiwul.pdfIn PDF document text
    • https://lea-inc.com/wp-content/plugins/super-forms/uploads/php/files/33c10ce8c6fef717e3e1eaf4d50c9e7f/zefavuvatoxufonalozevigaw.pdfIn PDF document text
    • http://abwmountvernon.com/uploads/files/noxiwafixi.pdfIn PDF document text
    • http://entiambalaj.com/upload/file/82268828914.pdfIn PDF document text
    • http://www.fsnn.se/wp-content/plugins/formcraft/file-upload/server/content/files/1606f67dad432e---didesuvulanekakurofawised.pdfIn PDF document text
    • http://graciaindoutama.com/kingkong/userfiles/files/18464384571.pdfIn PDF document text
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bf9432c7ff---noxotezezapixikuxuvoges.pdfIn PDF document text
    • http://www.orhancoskun.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2b252edc1b---93339134695.pdfIn PDF document text
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c96280380b3---xobavonunesa.pdfIn PDF document text
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/160b450ab03505---11878065007.pdfIn PDF document text
    • http://vssteel1999.com/ckeditor/userfiles/files/79869454461.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=bariatric+psychological+evaluation+near+mePDF 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_off0000eeb4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEB4 16676 bytes
SHA-256: 98c6dc40465a465175a82af11109e1b3aa29fb5ed7ecba092172c2ec04527260
font_01_sfnt_off00011a43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A43 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001325a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1325A 11156 bytes
SHA-256: 82a5c34fef4586cda1d96254fad72684d02fdf92c41525281039a5ec35eb443e