Malicious PDF — malware analysis report

Static analysis result for SHA-256 f21b5a48d7fbdba6…

MALICIOUS

PDF

75.9 KB Created: 2021-09-11 09:15:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: e4a123c0228bceb337f6742dcf699bf3 SHA-1: abdbd8dc0db4d3c5ccd0f76698872b81607b037b SHA-256: f21b5a48d7fbdba616a16fdb6039c60a38f2eef0d2c63a05a79ac5567987b53a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF contains numerous embedded URLs, many of which point to disposable domains or compromised CMS upload storage, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious document delivery mechanisms.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://apvn.info/userfiles/file/vemibo.pdf In PDF document text
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133ebfd28e9c---gasuduz.pdfIn PDF document text
    • https://ofcourselc.com/admin/uploadsfile/30089128904.pdfIn PDF document text
    • https://hijaustabilo.com/contents/files/jimejotimajogaze.pdfIn PDF document text
    • https://wsbe17hongkong.hk/_bin/ckfinder/userfiles/files/firiludexisebekav.pdfIn PDF document text
    • https://www.karelo.com/uploads/File/wuniwodufetuker.pdfIn PDF document text
    • https://giltmorestukko.hu/ckfinder/userfiles/files/31067687238.pdfIn PDF document text
    • http://china-baby-clothes.com/d/files/zunasavonuwodoxogaxoje.pdfIn PDF document text
    • http://fertilityupdates.com/userfiles/files/36514191492.pdfIn PDF document text
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/3157b75a1b84cb2616e6138e8e0416fc/74253812715.pdfIn PDF document text
    • http://hoteldanang.com/uploads/images/files/lefewajomufiditadimaraw.pdfIn PDF document text
    • http://abcbyspu.com/ckfinder/images_store/files/zuzalijifulotekumavixex.pdfIn PDF document text
    • http://cs-web-design.de/ablage/userfiles/files/39203512608.pdfIn PDF document text
    • http://csc028.com/userfiles/file/20210907234552_g171zt.pdfIn PDF document text
    • https://rdsdealers.com/ckfinder/userfiles/files/29063443734.pdfIn PDF document text
    • https://dodatkireklamowe.pl/web/uploads/files/kotuvamelaxasega.pdfIn PDF document text
    • https://harshahometutors.com/uniformkontakt/userfiles/image/files/11254708835.pdfIn PDF document text
    • http://zakuskymoser.cz/www/ckfinder/userfiles/files/1030440039.pdfIn PDF document text
    • https://robertbah.si/files/file/xaridoxinazutabodawewubew.pdfIn PDF document text
    • http://techbis.pl/files/file/ranude.pdfIn PDF document text
    • http://zeshengtecphar.com/UploadFiles/FCKeditor/20210909201042.pdfIn PDF document text
    • http://cdkuys.handysociality.com/upload/files/53437093491.pdfIn PDF document text
    • http://cukiernia-waltar.pl/qcms/userfiles/file/34866944170.pdfIn PDF document text
    • http://leinerpakgelatine.com/survey/userfiles/files/suponu.pdfIn PDF document text
    • https://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/161366b235b607---38349825436.pdfIn PDF document text
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613c0c5db245c---kumifuxasenen.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=paid+vpn+pro+for+android+apkPDF 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_off0000c3ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC3EA 17740 bytes
SHA-256: b84b495aa93f87d8a834f11344fe52def6169eb604ae845c1199a97184f14132
font_01_sfnt_off0000f1cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1CD 10204 bytes
SHA-256: 17ce5bda2b83b00ec6e8005b9051c8b75d3a2f7b771edd6e3de815762c89ede1
font_02_sfnt_off000108bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108BD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1