Malicious PDF — malware analysis report

Static analysis result for SHA-256 7a6858d82a3c4c53…

MALICIOUS

PDF

80.4 KB Created: 2021-09-18 23:07:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: bc261dd9f22cfa07172fe8c31f7a316e SHA-1: 9552c67e695501a8c24ce339f814f14ecff11544 SHA-256: 7a6858d82a3c4c532ec84fa0709d32bcbd640871603f934ea9405a7148f4ace2
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to potentially compromised CMS upload directories or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were directly extracted, the structure and URL patterns suggest this PDF is part of a link farm or SEO poisoning campaign, likely intended to lead users to malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 http://szwygs.com/upload/zawojunomunizexuma.pdf In PDF document text
    • http://harryreichert.de/uploaded_pics/News/file/bedavagekuzutuv.pdfIn PDF document text
    • http://kabaretyimpresariat.pl/Upload/file/rokixitoxerugisubar.pdfIn PDF document text
    • http://dyglas.com/userData/board/file/fosuzoxit.pdfIn PDF document text
    • http://greenbrier101.com/userimages/61696954293.pdfIn PDF document text
    • https://rpaxis.net/userfiles/file/kowelipipofami.pdfIn PDF document text
    • http://methese.com/upload/files/58184597499.pdfIn PDF document text
    • http://air-ned.com/uploads/files/51356061436.pdfIn PDF document text
    • https://medbioplast.com/klucharnet/images/file/dokiwunuvawekeludu.pdfIn PDF document text
    • https://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/2c832f81ce1facebae69a1e4a878fc5d/70360001956.pdfIn PDF document text
    • https://www.isgs.org/wp-content/plugins/super-forms/uploads/php/files/248107705f6990e45400106c2ca8b567/pukujajapi.pdfIn PDF document text
    • http://xinxinhouseware.com/uploadfile/files/47309008905.pdfIn PDF document text
    • http://mitcostruttori.it/userfiles/files/57220335862.pdfIn PDF document text
    • http://absolutelyneon.com/userfiles/file/62075085922.pdfIn PDF document text
    • https://asset-books.com/userfiles/file/18057930337.pdfIn PDF document text
    • https://autoradiator.mn/uploads/ckfinder/files/kiwawoxukopogunogeso.pdfIn PDF document text
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1614394d28f498---nokarumawizo.pdfIn PDF document text
    • https://suacuacuontoanphat.com/upload/files/figebiwis.pdfIn PDF document text
    • http://www.tlo.ntou.edu.tw/ckfinder/userfiles/files/besegusorafilozitopuz.pdfIn PDF document text
    • https://www.huaikrachaohospital.go.th/assets/global/lib/ckfinder/userfiles/files/38383419891.pdfIn PDF document text
    • http://kenhuffbuilders.com/userfiles/file/86172738675.pdfIn PDF document text
    • http://ros-grad.ru/fck_editor_files/files/51652800536.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=hack+vip+shadow+fight+2PDF 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_off0000d4c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4C8 17544 bytes
SHA-256: b36591f9c54bc962c480028c6045ff1cbb057f2f87cfa2a9020823a489d6b0eb
font_01_sfnt_off000102a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102A5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011abc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11ABC 10872 bytes
SHA-256: 6ad0295c87cf625a3d1136755099e974bc4bddfbf19cadcad78e5a04a69271dd