Malicious PDF — malware analysis report

Static analysis result for SHA-256 21f885a4fb9c8ba4…

MALICIOUS

PDF

106.4 KB Created: 2021-08-07 15:00:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: c5c9129c9ef5239b0bce727bf3f976a5 SHA-1: dd00d5ca9e5062a5b843878794a048107ba4d4e9 SHA-256: 21f885a4fb9c8ba4ab73877493277ddf3474e0e72b3bc1aad29facfcdaa071ed
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous embedded URLs, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this. No scripts were extracted, but the overall structure and URL distribution point to a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9901

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://crewmak.ru/uplcv?utm_term=grachi+1+temporada+capitulo+5+completo+en+espa%C3%B1ol+latino+hd PDF link annotation
    • https://biomedchita.ru/imeg_master/file/mazorofuzozozelomonogi.pdfIn PDF document text
    • https://ubitanduk.com/contents//files/4679561889.pdfIn PDF document text
    • http://ifaistos.reality.gr/~triantaf/images/file/18956362048.pdfIn PDF document text
    • https://verner.lt/images/files/fokawipobutu.pdfIn PDF document text
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070b186f2584---2730564640.pdfIn PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a77f2eacd25---50914155181.pdfIn PDF document text
    • http://www.sarajevo-inn-grunewald.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac94330efcd---4012734004.pdfIn PDF document text
    • http://brezov-gaj.si/uporabnik/file/9351683737.pdfIn PDF document text
    • http://vudafrique.com/wp-content/plugins/super-forms/uploads/php/files/ad0abff16ee874d6b414a2a1bd1850f3/14235065574.pdfIn PDF document text
    • https://hps-gruppe.com/wp-content/plugins/super-forms/uploads/php/files/hfirg2dqp1fddg363rib2om3lj/pafowiwezomajodamifekume.pdfIn PDF document text
    • https://mlbcsimleague.com/ckfinder/userfiles/files/rajajofamejomukaduxuma.pdfIn PDF document text
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160db9757803df---wilikata.pdfIn PDF document text
    • https://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/d75317d81810fc5233deae175f82ddd9/23938463600.pdfIn PDF document text
    • http://mmckno2010.zkosuchdol.info/files/69116392367.pdfIn PDF document text
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/16102ec03121a1---bujulegumixe.pdfIn PDF document text
    • http://humboldthighclassof79.com/clients/1/19/19f040aad945c40a0acbd79abd3dc6cb/File/49718914556.pdfIn PDF document text
    • https://teenvolunteerhouston.org/wp-content/plugins/super-forms/uploads/php/files/e74d3836b631a30bfa6f1d415bed9675/46493879874.pdfIn PDF document text
    • http://infrabud.eu/fckpliki/file/wurunateb.pdfIn PDF document text
    • http://watch62.ru/files/files/11585985674.pdfIn PDF document text
    • http://debden.org/userfiles/file/68923150992.pdfIn PDF document text
    • https://giasusinhvien.net/upload/files/wawinajoditevim.pdfIn PDF document text
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606eff6ebab00---bipukezutodiwes.pdfIn PDF document text
    • https://infravoip.com/wp-content/plugins/super-forms/uploads/php/files/ab4f03803c6c6c6ca34390b2cb0501f4/rujowomefudipejo.pdfIn PDF document text
    • http://hoangduy.vn/vn/files/wapix.pdfIn PDF document text
    • http://aaaexpressac.com/userfiles/file/17461292440.pdfIn PDF document text
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a882e6ca1a1---10791715813.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_off00013097.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13097 21000 bytes
SHA-256: a9f8c49621fb1967cc59f687eaee13e2fb4b2f61b0fe8a97b3ed290c92d68555
font_01_sfnt_off00016592.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16592 11308 bytes
SHA-256: f2c889e3bd66564b4718d31c280553897c84880216f5cda8632a18e4892f637c
font_02_sfnt_off00017fcd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17FCD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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