Malicious PDF — malware analysis report

Static analysis result for SHA-256 951f1e473edfd338…

MALICIOUS

PDF

82.1 KB Created: 2021-09-19 12:20:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: cbf296183e55324681ad918ef4e718cf SHA-1: dc40ce273e7b3dfe3e017a2eb2c9d43cf86729af SHA-256: 951f1e473edfd3383161bec9be0c4d750e575789781ff28e9e20974dc6655138
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, with numerous URLs pointing to various domains, some of which appear to be compromised CMS upload storage. The presence of 'utm_term' parameters in some URLs suggests a phishing or SEO manipulation tactic to lure users to potentially malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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 https://irlanc.ru/uplcv?utm_term=the+walking+dead+webisodes+watch+online PDF link annotation
    • https://prettygreekvillas.com/admin/fckeditor/editor/filemanager/connectofile/51045861291.pdfIn PDF document text
    • https://wwa.bdbabymart.com/app/webroot/ckfinder/userfiles/files/tojigugowufinabofulin.pdfIn PDF document text
    • https://onsale.social-push.cc/data/fckeditor/files/zumuf.pdfIn PDF document text
    • http://bundoreh.com/fckeditor/files/file/53649769703.pdfIn PDF document text
    • https://classoft.ro/userfiles/file/7461658730.pdfIn PDF document text
    • http://tongrentangthai.com/UserFiles/file/sogofaj.pdfIn PDF document text
    • http://slhospital.com/upload/fckeditor/file/71013013091.pdfIn PDF document text
    • http://master-vin.ru/files/file/57438886006.pdfIn PDF document text
    • http://matrixuniverzum.eu/wp-content/plugins/formcraft/file-upload/server/content/files/161402e4f789da---63684524970.pdfIn PDF document text
    • http://dobraukraina.org/sites/all/sites/dobraukraina.org/files/52656790069.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/uh5e18ov4an2p4b6vre314rrhh/netuwasoloremimaron.pdfIn PDF document text
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/16137cbf714fe5---53989494424.pdfIn PDF document text
    • http://ovecollection.com/royal/admin/images/products/file/jezojizomebuwenu.pdfIn PDF document text
    • http://www.advancedevents.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16130d003719c8---38121349810.pdfIn PDF document text
    • http://studiotecnicodambra.eu/userfiles/files/sobaxaxirikonu.pdfIn PDF document text
    • http://shamayachts.com/upload/file/7105994160.pdfIn PDF document text
    • https://mosoptagro.ru/wp-content/plugins/super-forms/uploads/php/files/aac3720c531709d04a630e4cc5ce05a4/zigugipukejofalasixegagim.pdfIn PDF document text
    • http://snuhonors.com/userfiles/file/75167033227.pdfIn PDF document text
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/c5f9dfc8575b24697b655d39076fcabf/91010344046.pdfIn PDF document text
    • https://interior-mark.com/ckfinder/userfiles/files/22058187091.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_off0000dcde.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCDE 17608 bytes
SHA-256: 8c64b171c8a2f1d282c8816b688ffba7761dbba06a85992e7d8e4fd8976eaccc
font_01_sfnt_off00010a78.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A78 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001228f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1228F 10832 bytes
SHA-256: f11b60c64af6d586412e37a80a501acc76613e29fb57437b83ab85cf051ec50f