Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f08a2157c8d5137…

MALICIOUS

PDF

81.3 KB Created: 2021-09-13 21:08:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 5504ed777a7c32ac24e3af8009959240 SHA-1: bbae1a2aff20250c15b73dd37555f51bea0b98c0 SHA-256: 3f08a2157c8d5137c7c48d40900b59da7e12d097390c75d0b86f6fddb624faa5
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to disposable hosting or compromised CMS uploads, characteristic of a link farm designed to lure users to malicious sites. ClamAV and an ML classifier flagged this PDF as malicious, specifically as a phishing trojan. The presence of external URIs and link farm heuristics strongly suggests a phishing or credential harvesting attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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://specialcats.nl/media/files/bapawisukakafob.pdf In PDF document text
    • http://aryajob.com/user_upload/file/mivubitaxipafibunovutunu.pdfIn PDF document text
    • https://lajovisena.com/gallery/file/vupinaremoluse.pdfIn PDF document text
    • http://ls12368.com/userfiles/file/fegatugisigelagizerovesej.pdfIn PDF document text
    • http://colegiosantarosa.com/uploads/imagem/file/76956659956.pdfIn PDF document text
    • https://travelone.ae/userfiles/files/sufudetuje.pdfIn PDF document text
    • http://svaz-podnikani.cz/files/file/nutinizavumigob.pdfIn PDF document text
    • http://honghuibio.com/d/files/fuzidimasutovugazumena.pdfIn PDF document text
    • https://vilus.cz/userfiles/file/totifaritinugawen.pdfIn PDF document text
    • https://vinocastillo.hu/editor_up/vulenumotewizegelezikufag.pdfIn PDF document text
    • http://bamor.org/userfiles/file/8116380361.pdfIn PDF document text
    • http://megatex-plast.ru/pub/file/wajipivigigoroxanuxuf.pdfIn PDF document text
    • https://malimbe.africa/wp-content/plugins/super-forms/uploads/php/files/7b9dee4000018b52d7f24e8717ba2135/2022651595.pdfIn PDF document text
    • http://www.bluefashion.cz/ckfinder/userfiles/files/54770954805.pdfIn PDF document text
    • http://tongkhomica.com/upload/files/kazimawewawezopasile.pdfIn PDF document text
    • http://storemisr.com/uploads/files/91981962486.pdfIn PDF document text
    • https://independentmusicleague.com/wp-content/plugins/super-forms/uploads/php/files/45a8d35ecde3ef9db5952b9c93540b3b/kuxefosomenujat.pdfIn PDF document text
    • https://vhssirimpanam.org/ckfinder/userfiles/files/62711001457.pdfIn PDF document text
    • http://xahscw.com/userfiles/file/rugijirewe.pdfIn PDF document text
    • http://paradisoseminatrici.it/userfiles/files/17581492400.pdfIn PDF document text
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/307f453058dca860ea50922f0c8ee610/525080530.pdfIn PDF document text
    • http://marta-galan.com/files/varios/file/90906141851.pdfIn PDF document text
    • http://cambridgekapurthala.com/damana/userfiles/file/7935898578.pdfIn PDF document text
    • http://nb-magnet.com/upload/files/98507898025.pdfIn PDF document text
    • http://sungwoo-n.com/userfiles/file/94686569400.pdfIn PDF document text
    • http://mecateengenharia.com.br/ckfinder/userfiles/files/wepajevula.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=update+install+app+play+store+downloadPDF 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_off0000db8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB8B 10592 bytes
SHA-256: 0aa03f1c3473eef6b65809296b303824a4a632e33dacf9fe0b1ea1c334de6620
font_01_sfnt_off0000f3f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3F2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010c04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C04 16868 bytes
SHA-256: b967f4ab35ae7e9afe16dae354f4b4046519dc482b31847b5515776955ae93f5