Malicious PDF — malware analysis report

Static analysis result for SHA-256 41f08eec72b95c19…

MALICIOUS

PDF

79.0 KB Created: 2021-09-12 19:09:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 0c4e8beca1654ead04e9f9d1db7e6ca1 SHA-1: 70adbf9beb426ead771ad858cd65ae96e675f993 SHA-256: 41f08eec72b95c198315349893daef00dcb4da1500ac12947a0677ae90fc0db3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains a large number of embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed for malicious redirection. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. No scripts were extracted, and the document body was unreadable, so the primary attack vector appears to be the exploitation of user trust through deceptive links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9735

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://lemonsport.sk/upload/file/25583637447.pdf In PDF document text
    • http://tafgambiatours.com/userfiles/file/60785012600.pdfIn PDF document text
    • http://jimsclub.net/new/board/img_tinfo/file/20210902135431.pdfIn PDF document text
    • https://fiberglasssupplydepot.com/userfiles/file/26906989419.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613bd32ba4da5---silawejubidupomob.pdfIn PDF document text
    • http://behtarinekhodetbash.com/files/files/93913847147.pdfIn PDF document text
    • https://tolgyesvolgy.hu/userfiles/file/logorivoratojopifanejore.pdfIn PDF document text
    • https://altinhediyeler.com/calisma2/files/uploads/42875326833.pdfIn PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613a3975a706f---gunefexuwagalokoz.pdfIn PDF document text
    • https://itexpertdog.com/upload/files/mudaf.pdfIn PDF document text
    • https://readxyz.com/wp-content/plugins/super-forms/uploads/php/files/ea1603814139a6c4c52761c94bc60826/19514185552.pdfIn PDF document text
    • http://pro-group.ru/userfiles/files/lagotuf.pdfIn PDF document text
    • http://heryeryesil.com/resimlerfiles/31146440630.pdfIn PDF document text
    • https://lideregitimpaketleri.com/calisma2/files/uploads/9742243176.pdfIn PDF document text
    • http://forti.in/userfiles/file/34197956320.pdfIn PDF document text
    • https://www.agencesramos.com/ckfinder/userfiles/files/69828116150.pdfIn PDF document text
    • https://christianbelieversmatrimony.com/web/christiansbelieversmatrimony/photos/ckeditor/files/68703364840.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/gn47d6mg5heuom6c593gslfbj6/93273609240.pdfIn PDF document text
    • https://asaptransfers.co.uk/wp-content/plugins/super-forms/uploads/php/files/bb8ba8030fe55a42970d2fa57ff73551/75695644625.pdfIn PDF document text
    • http://autosoftware.company/autoresponders_images/files/sozeserivugavulefopi.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/nbl729appokt0mq7smh09aji30/morefozazakavofi.pdfIn PDF document text
    • http://vincentianssjp.com/userfiles/file/90919079336.pdfIn PDF document text
    • http://kozhencherrymtc.org/userfiles/file/31578793985.pdfIn PDF document text
    • https://literie-depot.fr/UserFiles/file/9046023547.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/161383029645a2---soweluwuxubibusemureloxag.pdfIn PDF document text
    • http://giaphatmed.com/upload/file/21413841852.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=android+sdk+tools+managerPDF link annotation
    • 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_off0000d811.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD811 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f028.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF028 10664 bytes
SHA-256: 9b0f9d713a02998bc2dcf9a799fe09d55429902072bed82087b085c758f0778d
font_02_sfnt_off00010862.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10862 17464 bytes
SHA-256: 19280455848d4bd1950fef57dbd7eb7b30c027d1a9cba064a35557d5d8cb6579