Malicious PDF — malware analysis report

Static analysis result for SHA-256 531c077ac5081b98…

MALICIOUS

PDF

80.9 KB Created: 2021-09-01 03:47:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: c259bbaf6caf28f3590e44724874359a SHA-1: ac7cd86fcb2a0f0b9eede2008daed71e849ecc56 SHA-256: 531c077ac5081b98096c02a293b91861a303d9a872b13b429d5696baf1528e90
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised or disposable hosting, indicating a link farm for SEO manipulation or phishing. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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.primalegal.eu/wp-content/plugins/super-forms/uploads/php/files/0fs9mhk2b7s519b3mt4m6do7b5/87492249960.pdf In PDF document text
    • http://xn--80aaeiengkwpz6p.xn--p1ai/pub/file/17764518296.pdfIn PDF document text
    • https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/e17473bd4c2c95e4aa4de17238588363/10138178519.pdfIn PDF document text
    • http://lulanjina.net/upload/files/fosonil.pdfIn PDF document text
    • https://aulacvn.com/upload/fck/file/xeloparepakinivifuf.pdfIn PDF document text
    • http://www.tekkoo.net/images/library/File/xojimigizetupogem.pdfIn PDF document text
    • https://boucherienabli.com/uploads/FCK_files/file/88590516712.pdfIn PDF document text
    • http://edgecs.net/documents/76664297304.pdfIn PDF document text
    • https://readxyz.com/wp-content/plugins/super-forms/uploads/php/files/0c43bc2ac28d1a2506feb1a483eaa517/tifujevidisatuxejapiwumil.pdfIn PDF document text
    • http://www.ashtralmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609080f3e91b9---54027792590.pdfIn PDF document text
    • http://rgjbreunion.com/clients/6/69/6950e03db8b1ea894755b369f0a03c31/File/menikixexofape.pdfIn PDF document text
    • http://aftckwt.com/uploads/file/zonadobebitojimimefe.pdfIn PDF document text
    • http://inncredel.com/uploads/tigebunenosulig.pdfIn PDF document text
    • https://newchat.xyz/js/ckfinder/userfiles/files/xikuposopivatokubojibode.pdfIn PDF document text
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/160e0b9dee5d4b---biful.pdfIn PDF document text
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/160773210acff0---44239457031.pdfIn PDF document text
    • https://chungcungoaigiao.net/uploads/files/20990770082.pdfIn PDF document text
    • https://eletroluz-al.com/_IMG/img_internas/file/negobajowuz.pdfIn PDF document text
    • http://vertracapital.com/uploads/files/66304361593.pdfIn PDF document text
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/160c4b6abd3edb---kezibigasowuwesinuku.pdfIn PDF document text
    • https://www.kcequipment.com.au/wp-content/plugins/super-forms/uploads/php/files/496fff55a01e29a06875207126c27d0e/nepudupisijuxofimoger.pdfIn PDF document text
    • http://mdbim.pl/ubezpiecz/obrazy/file/lufulixogut.pdfIn PDF document text
    • https://md-bud.pl/szklo/photos/file/33149100599.pdfIn PDF document text
    • http://fly.no1-yes.com/userfiles/file/4255585633.pdfIn PDF document text
    • http://vmkmsz.hu/userfiles/file/99940204865.pdfIn PDF document text
    • https://shotclock.ca/wp-content/plugins/super-forms/uploads/php/files/2dee1ad73f7210daf40f03622485bf30/13189726738.pdfIn PDF document text
    • http://way-of-spirit.ru/upload/file/vemawa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=how+to+make+a+graph+with+line+of+best+fit+on+excelPDF 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_off0000d6a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6A8 11340 bytes
SHA-256: 37fe56591d5a6677b0d1b60592e85787236afbe05de7946e11586d59317367ba
font_01_sfnt_off0000f0ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0EF 17096 bytes
SHA-256: 7486c632549d35dc927ba6c7eeed2f96ce075712f5ad0cc224632800947d45b5
font_02_sfnt_off00011d0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D0C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1