Malicious PDF — malware analysis report

Static analysis result for SHA-256 f16137d4e1e96be5…

MALICIOUS

PDF

71.5 KB Created: 2021-09-25 07:14:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 1aac0df7da75b0d8d61687907b03fbe7 SHA-1: 7a6e751612e8ba70c1b931378c6df252bb251282 SHA-256: f16137d4e1e96be57688851436ba325702445d40d469a27c743ee98da509c69f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs that point to various domains, many of which are flagged as link farms on disposable hosting or compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the PDF structure and heuristic firings suggest it's designed to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://synerhu.ru/uplcv?utm_term=call+prank+apk PDF link annotation
    • http://tiquital.com/documentos/file/5228333616.pdfIn PDF document text
    • http://sb-78.ru/files/file/gibafuloxokerosapeb.pdfIn PDF document text
    • https://bunian-co.com/other_files/File/42548517542.pdfIn PDF document text
    • http://novosib-sport.ru/ckfinder/userfiles/files/24088890285.pdfIn PDF document text
    • https://osikovo.eu/webroot/img/content/files/jejitepafogekax.pdfIn PDF document text
    • http://klhl.com/userfiles/file/lowudij.pdfIn PDF document text
    • https://pointwebhost.com/calisma2/files/uploads/8955709726.pdfIn PDF document text
    • https://fptica.ru/images/file/gawobevutunaxojebej.pdfIn PDF document text
    • http://huichem.com/ckfinder/userfiles/files/waleledexuxiferinekiba.pdfIn PDF document text
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16130de7a443cb---tomaxakezinojonelaluxof.pdfIn PDF document text
    • http://ibrahimabuomira.com/ckeditor/ckfinder/userfiles/files/xijofuzoliduwuwutik.pdfIn PDF document text
    • https://laughteronlineuniversity.com/images/upload/files/sikuxabevowuvuxur.pdfIn PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1614d17ba28595---lalutijatebuwudepit.pdfIn PDF document text
    • http://sjatupornservices.com/file_media/file_image/file/botigesowixutitojaga.pdfIn PDF document text
    • http://dintainoodle.com/uploads/files/4940401944.pdfIn PDF document text
    • https://orangcar.com/app/webroot/upload/files/sororeravulezasaxivop.pdfIn PDF document text
    • http://hurtowniagrafit.pl/userfiles/file/1238408465.pdfIn PDF document text
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/161332516e3bcb---70554481871.pdfIn PDF document text
    • http://controlsystemco.com/cache/fck_files/file/17393395286.pdfIn PDF document text
    • https://tractorpulling-emmeloord.nl/upload/file/94391042341.pdfIn PDF document text
    • http://ntep2008.com/UserFiles/File/befewaxobebon.pdfIn PDF document text
    • https://b2cdemo.tickets.com/content/files/mexoxuxed.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_off0000b56e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB56E 9756 bytes
SHA-256: 3eb94543131998e21b7c32c021372abf06b2e19d4fc0a5aa80532250b5c87ec2
font_01_sfnt_off0000cad2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAD2 17656 bytes
SHA-256: 3473c0f337f7454f77d6a3102409f5dbf77dfbe35d72ee299187ccf3dbe8af75
font_02_sfnt_off0000f8ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8EE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1