Malicious PDF — malware analysis report

Static analysis result for SHA-256 85e91b2151750088…

MALICIOUS

PDF

110.1 KB Created: 2021-09-05 09:21:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 9f510fe2a5981ea01a5c46d59e33cf1e SHA-1: 498851400c2eb25163c890dee07b0a81e58f263c SHA-256: 85e91b21517500881337b192f90678ce0ca3863f8a821cd37c6eb51991aca920
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links pointing to websites hosted on compromised or disposable domains, identified by heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM'. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of many unknown reputation URLs reinforces the suspicious nature of this link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9979

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://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/161160a6231e5f---kegadol.pdf In PDF document text
    • https://smsenerji.com/resimler/files/tefadibofazonug.pdfIn PDF document text
    • https://parc-hotel.info/file/62580857139.pdfIn PDF document text
    • http://historico.uts.edu.co/portal/app/ckfinder/userfiles/files/wijesedej.pdfIn PDF document text
    • http://seoaudytor.pl/userfiles/file/79529115523.pdfIn PDF document text
    • http://asalsold.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8d0b0b3cbb---fezalufo.pdfIn PDF document text
    • http://omatsuri.kr/data/userfiles/files/62291930373.pdfIn PDF document text
    • https://visaonline-vn.com/wp-content/plugins/super-forms/uploads/php/files/pfbalu510ggtm5m2qpj90onojs/20258794975.pdfIn PDF document text
    • http://comicpapyrus.com/wp-content/plugins/super-forms/uploads/php/files/918a200ab42160736c030c960a7d416c/babofatone.pdfIn PDF document text
    • http://cpgny.com/userfiles/files/69515297303.pdfIn PDF document text
    • http://agendaalzheimer.org/files/galeria/files/wuvesizezozogolawise.pdfIn PDF document text
    • https://www.charroninc.com/wp-content/plugins/super-forms/uploads/php/files/484b3f2c5ae1af7710ca6fd669905e53/55906206837.pdfIn PDF document text
    • http://camelliafb.com/uploads//files/202108051002324125.pdfIn PDF document text
    • https://spotiverify.com/ci/userfiles/files/manujodefutegorap.pdfIn PDF document text
    • http://christmaslandint.com/userfiles/44706798512.pdfIn PDF document text
    • http://yasairamenbar.com/uploads/files/18446628349.pdfIn PDF document text
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aaad6292b6c---bojotudowevulunetal.pdfIn PDF document text
    • http://sewakendragroup.com/userfiles/file/govosub.pdfIn PDF document text
    • https://tirthmobile.com/wp-content/plugins/super-forms/uploads/php/files/bocno4vcuia73oflufgpiq0fbm/jipiwegidebeme.pdfIn PDF document text
    • http://www.pethouse.es/ckfinder/userfiles/files/ruredademinazinojokigu.pdfIn PDF document text
    • https://airflow-skateboards.com/upload/file/zetofejezefivudodago.pdfIn PDF document text
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/c06e9ca804d3da7b48435d5111344526/pavebisadikofi.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/fffsmb76ifepuf0vgs3snv3r25/84075499317.pdfIn PDF document text
    • http://mtlebanon62.com/clients/5/5e/5ee551a8be14a26d7d76bc5e90dd1372/File/bufudajirodojejijovebe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=instructional+design+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_off000148ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x148EC 10848 bytes
SHA-256: a5bdcfd1fa1175acd8eed9fdad97c42ac73142e9bee8a7e9e98197b207bc4c87
font_01_sfnt_off000161dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x161DD 18908 bytes
SHA-256: 970274c77250de46c223846f55005098df05bf9a23002d854f3f622911dcf6fa
font_02_sfnt_off000192c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x192C3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1