Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b762e0cf1f5c7b5…

MALICIOUS

PDF

81.7 KB Created: 2021-08-15 08:32:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: d6d358a7def8ba9579b5c094b741eded SHA-1: ac8456ac44ebe55163f38d63009a0c4569eea87a SHA-256: 4b762e0cf1f5c7b5f3f8ceecca1316d28113ad2e03a0988c442b0f1077f894f2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised WordPress uploads and other disposable hosting, suggesting a phishing or malware distribution scheme. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with attempts to redirect users to malicious sites, likely for further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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.laterveer-biesenbeek.nl/ckfinder/userfiles/files/kuruzelekonibuvarupekuta.pdf In PDF document text
    • https://dazzlin.co.uk/wp-content/plugins/super-forms/uploads/php/files/1c64619ae2c030907856c370cb7aab95/lilerat.pdfIn PDF document text
    • http://vasilii-orlov.fun/wp-content/plugins/super-forms/uploads/php/files/c4d64808411e03420f238a4eaa132680/bafanulizuradanu.pdfIn PDF document text
    • https://soudurelausiere.ca/upload/editor/file/33681463052.pdfIn PDF document text
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16087c3e763eb7---89612846181.pdfIn PDF document text
    • http://opakowania-loga.pl/zdjecia/fotki/file/79304853886.pdfIn PDF document text
    • http://aibasylhet.edu.bd/app/webroot/ckfinder/userfiles/files/giwegibewotedujop.pdfIn PDF document text
    • https://nutricount.cz/UserFiles/File/lakijifade.pdfIn PDF document text
    • https://spencershaulageltd.co.uk/wp-content/plugins/super-forms/uploads/php/files/738257122608a91b46b75c453a2b8f67/suvozigesoxaluxar.pdfIn PDF document text
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f37261aa85---wukevuzowemap.pdfIn PDF document text
    • http://www.ufolep-69.com/contenus/files/5310714924.pdfIn PDF document text
    • https://mlmrockstars.com/ckfinder/userfiles/files/77959998922.pdfIn PDF document text
    • https://klcmekatronik.com/ckfinder/userfiles/files/29963019150.pdfIn PDF document text
    • http://eau-msu.ru/ckfinder/userfiles/files/77051799443.pdfIn PDF document text
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160944758780eb---simeroxi.pdfIn PDF document text
    • https://www.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b889c8b97c6---40289265293.pdfIn PDF document text
    • http://nanumed.ro/uploads/files/91524711542.pdfIn PDF document text
    • https://relaxationplusmn.com/wp-content/plugins/super-forms/uploads/php/files/c343ab7eaf1cd436a0ef2e43980813b4/74454403158.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=examen+diagnostico+para+ingreso+a+secundaria+pdfPDF 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_off0000d0f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD0F6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e908.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE908 20992 bytes
SHA-256: cad272a4ccf297c27220ab66a4e21bcba957f50e744171a06511be3459b8b5aa
font_02_sfnt_off00011d8d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D8D 11100 bytes
SHA-256: c3199dbb9164270781cb25a4ec400f669f5a9fcdc65639a1df7a6c09e10c4db3