Malicious PDF — malware analysis report

Static analysis result for SHA-256 55af465fa1f5da26…

MALICIOUS

PDF

83.4 KB Created: 2021-09-10 06:22:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 767b99837ec961ee1a5d528814015c00 SHA-1: 65efa241cc9f8e3120e68f5261816feb59d603db SHA-256: 55af465fa1f5da260e6479802e0cdece4fb991ec2b1a12cc79a028df5ac32b81
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The file is a PDF containing numerous embedded URLs, many of which point to compromised websites or disposable hosting. Heuristics indicate this is a link farm designed to redirect users, likely to phishing sites or to download further malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, consistent with a phishing or malware distribution campaign.

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 https://irlanc.ru/uplcv?utm_term=play+store+latest+version+2021+apk PDF link annotation
    • http://proxkimya.com/resimler/files/20775493845.pdfIn PDF document text
    • http://sake2metustin.com/uploads/files/46717827614.pdfIn PDF document text
    • http://boilerservis.ru/uploads/files/51822260078.pdfIn PDF document text
    • https://tomorrowhubs.com/upload/users/files/39593601689.pdfIn PDF document text
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/16130b04879102---36266144434.pdfIn PDF document text
    • http://instalater-macecek.cz/klienti/devel/sneznerolby.cz/ckfinder/userfiles/files/17417280837.pdfIn PDF document text
    • http://vitalenzyme.com/uploads/fckupload/file/20745565324.pdfIn PDF document text
    • https://lrsdev.com/userfiles/file/68926618443.pdfIn PDF document text
    • https://myagenda.myagenda.cz/pictures/editor/files/retizovidakugi.pdfIn PDF document text
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/161330c722cac8---57073496355.pdfIn PDF document text
    • http://dobre-jaja.com/Upload/file/93070124156.pdfIn PDF document text
    • http://tw-sincere.com/upfiles/editor/files/dower.pdfIn PDF document text
    • http://qtjdb.com/UploadFile/2021/09/08/file/20210908_000823_108.pdfIn PDF document text
    • http://xn--80aamwn.xn--p1ai/userfiles/file/wamon.pdfIn PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a082f9abe0---75334414625.pdfIn PDF document text
    • https://walterchiropracticclinic.com/home/walter/public_html/ckfinder/userfiles/files/54515185709.pdfIn PDF document text
    • http://1544-7419.net/upload/fckeditor/file/91008743811.pdfIn PDF document text
    • http://mgmkt.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16133ac8580363---23432909007.pdfIn PDF document text
    • http://capmar.eu/userfiles/file/55928110770.pdfIn PDF document text
    • http://sloplast.com/userfiles/files/zazovibatimujolufisuwel.pdfIn PDF document text
    • https://slotpt2.com/contents/files/denogirude.pdfIn PDF document text
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/slhgaj27813c86539hureegpr2/jajetomoxese.pdfIn PDF document text
    • http://xn--zb0bw3kv4s8mn.com/upload/fckeditor/file/tivalamidiluxemetibopu.pdfIn PDF document text
    • http://ncdesign.it/userfiles/files/78878173288.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_off0000de27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE27 10812 bytes
SHA-256: a2cfd1d8d728c348954e03fc8be843eedd6f1a9b6b5b7240b5172e2ab3d25e54
font_01_sfnt_off0000f75c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF75C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010f6e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F6E 18380 bytes
SHA-256: 1e4dd3100e43e1e3ab410f5daba5c4486f75c948a054b2beb480c787b51ab497