Malicious PDF — malware analysis report

Static analysis result for SHA-256 b687e383b2b89970…

MALICIOUS

PDF

82.8 KB Created: 2021-09-07 08:06:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 813c44512fd28fc63ae3b72733eb224c SHA-1: 09d9214a169843be657448f5b3ce6ba5118fff2f SHA-256: b687e383b2b899701b712ce7d244aa6a2b7d6c4c322f3127902b617f42e8faf1
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm or phishing lure. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or SEO spam. No scripts were extracted, and the document body was unreadable, limiting further analysis of specific payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://teakdeck.pl/files/file/34552949157.pdf In PDF document text
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/a6a435d90490e9328066f098f0852271/16296993778.pdfIn PDF document text
    • http://fullcolorspandoeken.nl/userfiles/file/fagixu.pdfIn PDF document text
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d4691a973c---nokowe.pdfIn PDF document text
    • http://yigang-lin.com/uploads/files/202108270823164796.pdfIn PDF document text
    • http://ptk-astana.kz/wp-content/plugins/super-forms/uploads/php/files/65be48159d789b00ba29376c6004bdd2/nuvinivolosufiju.pdfIn PDF document text
    • http://dragonera.cn/admin/userfiles/file/79076339609.pdfIn PDF document text
    • http://rnralpha.cz/res/file/duwir.pdfIn PDF document text
    • http://w-mill.jp/images/file/pafavudujatejuzotiwamakur.pdfIn PDF document text
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607ce75eee669---90395839904.pdfIn PDF document text
    • http://aptekarynek.pl/zdjecia/fck/file/88311470141.pdfIn PDF document text
    • https://maugli24.ru/wp-content/plugins/super-forms/uploads/php/files/7cbe706d01dc3742c2b5155527443120/pilovojadupixapa.pdfIn PDF document text
    • http://fxlcd.com/upload/file/migomi.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/160f96da4be0eb---39233364494.pdfIn PDF document text
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160fe4c5d6fc55---bivinarolatoximig.pdfIn PDF document text
    • https://www.cocochan.com.pk/wp-content/plugins/super-forms/uploads/php/files/4285679055bf4f8340bfc25c04c974e3/vekarupemuvede.pdfIn PDF document text
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607be0199079f---54836576085.pdfIn PDF document text
    • http://zartmobilia.com/userfiles/file/20210830020923.pdfIn PDF document text
    • https://hram-uspeniya.ru/ckfinder/userfiles/files/virifobasugobaxaz.pdfIn PDF document text
    • https://sieseam.org/userfiles/files/kikegasolisapixaxej.pdfIn PDF document text
    • https://businesslife.com/content/files/68208557780.pdfIn PDF document text
    • http://rafaelstore.ru/upload/files/16356890310.pdfIn PDF document text
    • http://bdn10.cz/files/file/11380367869.pdfIn PDF document text
    • https://ipic.vn/userfiles/file/kulixaditabe.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/m0hk6kb8jvj2v9s5mm9oclc0e3/kewuwepotemozowuxuxo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=vw+tiguan+2015+owners+manual+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_off0000dbaf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBAF 17428 bytes
SHA-256: b5ce1634b9fe88c6d670ea3595cce7ba30c4fc27c5aaa2b87cdc0dabc0dd07fe
font_01_sfnt_off000108e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108E0 11424 bytes
SHA-256: e6c1076f1350753c0301d6eefc9b66a0eccef10f20078a15c4579560f2cb6cc4
font_02_sfnt_off000123cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123CF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1