Malicious PDF — malware analysis report

Static analysis result for SHA-256 400e3a921a78a826…

MALICIOUS

PDF

85.1 KB Created: 2021-09-14 04:38:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 700fc5108c915d796a131b87de0adad0 SHA-1: 5e88d9f335402f9efee4236a0301861665bb3366 SHA-256: 400e3a921a78a826244d2701fabab0252e70082f03d5ab9ec35bcd4a594ce363
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to potentially compromised WordPress sites or disposable hosting. The document body is heavily obfuscated and unreadable, providing no direct clues to its intent beyond what the heuristics suggest.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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.sloepverhuur-debiesbosch.nl/upload/files/18547054025.pdf In PDF document text
    • https://www.toptalentusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613df04067f34---81488565381.pdfIn PDF document text
    • https://ddc-touggourt.dz/ar/files/83784293680.pdfIn PDF document text
    • http://webinaris.biz/ckfinder/userfiles/publics/files/nutisimuguziju.pdfIn PDF document text
    • http://fapannimario.it/userfiles/files/12452990458.pdfIn PDF document text
    • https://gazeta-msp.pl/user_files/File/rozuvun.pdfIn PDF document text
    • https://nirmalujjwal.com/public/ckfinder/userfiles/files/61145133980.pdfIn PDF document text
    • http://rund-sro.cz/UserFiles/File/povoxozenedexavur.pdfIn PDF document text
    • https://tocgia247.com/wp-content/plugins/super-forms/uploads/php/files/5ps66dh1at4hil8gm4kkneo0vv/fubaxigebizapefojase.pdfIn PDF document text
    • http://ttccid.com/userfiles/files/70659281539.pdfIn PDF document text
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/1613e5372199f7---54159934207.pdfIn PDF document text
    • https://nistd.in/userfiles/file/vofeveleta.pdfIn PDF document text
    • http://elcolono.net/userfiles/files/3440842302.pdfIn PDF document text
    • http://hzzxtl.com/UploadFile/file/20210910061752250.pdfIn PDF document text
    • http://wooshin.kr/uploaded/file/644880118613c46d018b47.pdfIn PDF document text
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/32ca1f37c4ef490f79937e2b740d753f/30094431899.pdfIn PDF document text
    • http://bpabv.nl/uploadfiles/file/92988184820.pdfIn PDF document text
    • http://dentalweek.eu/userfiles/files/21924068159.pdfIn PDF document text
    • http://gestioniarmatoriali.it/25815573986.pdfIn PDF document text
    • http://villaturri.it/wp-content/plugins/formcraft/file-upload/server/content/files/1612f21b6940a5---18611431226.pdfIn PDF document text
    • https://congthuonghotel.vn/app/webroot/files/images/pages/files/56770634804.pdfIn PDF document text
    • http://www.sport-konyv.hu/userfiles/file/21425934736.pdfIn PDF document text
    • https://yenicekentkaplicasi.com/userfiles/file/2694096656.pdfIn PDF document text
    • http://es-manzokudou.com/yamituki-n/uploads/files/99106231180.pdfIn PDF document text
    • http://sissonne.hu/editor_up/77406383944.pdfIn PDF document text
    • http://www.tm-africa.com/beta/public/uploads/cms_filescms_files/13028476228.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=hoe+vind+ik+mijn+android+telefoonPDF 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_off0000eade.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEADE 16440 bytes
SHA-256: 1992b0d7dcdb94b55a7d25198ef2ad207046c8925828cecacf9c4b095e1018de
font_01_sfnt_off000115a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115A8 10624 bytes
SHA-256: 057edc2442ca2c4ae648b3707159ab22c79cd51b6630ffb8af7d7cb99ee42bcc
font_02_sfnt_off00012dd9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DD9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1