Malicious PDF — malware analysis report

Static analysis result for SHA-256 f637df35b9b23666…

MALICIOUS

PDF

85.1 KB Created: 2021-09-06 13:16:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: b43a700c3c58d8ed16f159c073d2d360 SHA-1: 08fc1efad405f3a79e082ebaa9883fee91d50295 SHA-256: f637df35b9b236665fde67738c30476356c3de7ac5b1b9480fae8444054a4ea8
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://shophouse.info/images/files/bufiwuwikivopirawoj.pdf In PDF document text
    • http://scoutpate.com/userfiles/file/tarafixumuxugijatevobaf.pdfIn PDF document text
    • http://szymonadamczyk.pl/uploads/fck/file/rivezotuvewasutiwemunevo.pdfIn PDF document text
    • https://pima-alarms.net/slicice/file/jupupofipenidasaruwuduxak.pdfIn PDF document text
    • https://dagvandearchitectuur.be/_files/file/tesuvoxotidubuses.pdfIn PDF document text
    • https://haps.company/wp-content/plugins/super-forms/uploads/php/files/b028244ed50631e667ca398c5c390f27/muwajifamajifa.pdfIn PDF document text
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9855e9da4---vametufujazulokowote.pdfIn PDF document text
    • http://nuraski.pl/wsg/userfiles/48100962399.pdfIn PDF document text
    • https://autosofortkauf.ch/wp-content/plugins/super-forms/uploads/php/files/5vdbnnrvimg39av59i2re95h46/xuwonaf.pdfIn PDF document text
    • https://ph2020.org/ckfinder/userfiles/files/79693167755.pdfIn PDF document text
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/7a4b81a3bbb11d889b80fe00a506407b/fibetawuro.pdfIn PDF document text
    • http://skupka23.ru/upload/m/nipixitejagazewepitugapos.pdfIn PDF document text
    • https://smilepath.com.au/wp-content/plugins/super-forms/uploads/php/files/636a82da0659297c6070a17a5f03f7f7/zijumagoguz.pdfIn PDF document text
    • https://suavitinhtannha.net/upload/files/39076078447.pdfIn PDF document text
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/16079547d7baf8---gutaxikakibitigikafew.pdfIn PDF document text
    • https://glowskincare.net/wp-content/plugins/super-forms/uploads/php/files/c0a76145c5a5327888686b3ef00a5360/89705908472.pdfIn PDF document text
    • http://trackeg.com/en/wp-content/plugins/formcraft/file-upload/server/content/files/16135cd042601f---98275151492.pdfIn PDF document text
    • http://americandeliorder.com/uploads/files/dazelubumetumudux.pdfIn PDF document text
    • http://bonfiremadigan.com/uploads/fckeditor/file/bigexagoduvafinulosisipel.pdfIn PDF document text
    • https://hamasataccessories.com/userfiles/files/dijazuzexoguporepukeb.pdfIn PDF document text
    • https://naseeha.org/wp-content/plugins/super-forms/uploads/php/files/1ee90177b8a4b3cd979864413221a419/69283189654.pdfIn PDF document text
    • http://vincityhomes.vn/wp-content/plugins/super-forms/uploads/php/files/5huikorf98s636s2gtldgap665/47514659082.pdfIn PDF document text
    • http://trainternational.in/wp-content/plugins/formcraft/file-upload/server/content/files/16078ac1208b75---tojijikufi.pdfIn PDF document text
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609f126045f38---disavipulobaxerefez.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=tipos+de+tendido+de+cama+en+enfermeria+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_off0000e73d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE73D 10700 bytes
SHA-256: a86bb328522ec95497710556aaf60949f55f5606091ed63139e12ad2d1369f0c
font_01_sfnt_off0000ffce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFCE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000117e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117E0 18516 bytes
SHA-256: bc4cb0b0342aa0a02f36c79ad31a41c8e1ea047b1bfb2aca51e8bd69b1204e18