Malicious PDF — malware analysis report

Static analysis result for SHA-256 0b139944e68834b5…

MALICIOUS

PDF

76.6 KB Created: 2021-10-18 21:58:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: f3c5cd4e2d1e6423580cceb82ad746e9 SHA-1: 8581890898e8b243088250c472c9086b7aec0f87 SHA-256: 0b139944e68834b56d9e05180ddf0507927bfcb16ed91ae7e9f5986580b35c9b
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware delivery. While no scripts were explicitly extracted, the nature of the embedded URLs and the PDF structure suggest potential exploitation or redirection mechanisms.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

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://infrive.ru/uplcv?utm_term=cableado+horizontal+y+vertical+en+redes PDF link annotation
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/8ba85a3d3432ddac41951943a7a7a87e/75894126074.pdfIn PDF document text
    • https://minlinart.com/archive/upload/files/17967850900.pdfIn PDF document text
    • http://kozhencherrymtc.org/userfiles/file/tunajupudavukijuver.pdfIn PDF document text
    • http://fabrikando.com/cmsimple/images/file/duvep.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141925c14750---siduzijibezivo.pdfIn PDF document text
    • http://exosportsante.fr/ckfinder/userfiles/files/9782195587.pdfIn PDF document text
    • http://movitecnic.com/ressource/site-image/files/929623536.pdfIn PDF document text
    • http://pasaru.com/upload/files/vakewidum.pdfIn PDF document text
    • http://parateam.cz/file/6627263072.pdfIn PDF document text
    • https://calson.garment-pro.com/ckfinder/userfiles/files/xuwumedifuxewujupulaze.pdfIn PDF document text
    • http://pibar.tw/uploads/files/202109280811347239.pdfIn PDF document text
    • https://impeka.lt/components/com_mijoshop/opencart/image/data/files/42054068032.pdfIn PDF document text
    • http://ottotech.center/userfiles/file/durebitupeniwad.pdfIn PDF document text
    • https://ww150003.linebot.net/upfile/files/20211018095646.pdfIn PDF document text
    • http://automsystem.com/UploadFile/file/20210910143413662.pdfIn PDF document text
    • http://frutapac.com/ckfinder/userfiles/files/61492633357.pdfIn PDF document text
    • https://npkfertilizerproduction.com/d/files/6711718227.pdfIn PDF document text
    • https://houstoncoinshow.org/FCKeditor/file/53770283737.pdfIn PDF document text
    • https://kalashad.com/userfiles/file/lefipev.pdfIn PDF document text
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613eec0ef2c53---zuvuf.pdfIn PDF document text
    • http://talani.nl/userfiles/image/file/88520384850.pdfIn PDF document text
    • https://zippy-inc.com/app/webroot/userfiles/files/32541843264.pdfIn PDF document text
    • http://kapfenberger-schuetzenverein.at/userfiles/file/lusataleke.pdfIn PDF document text
    • http://yule-sign.com/upload/editor/file/20211018061113.pdfIn PDF document text
    • https://ganport.pl/userfiles/file/32069502717.pdfIn PDF document text
    • https://lapdonline.org/file/53792384814.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_off0000c921.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC921 16424 bytes
SHA-256: 2b0c87c4b09be3e25207b0095ee65d3954385fdf20c04b85feadaabb6df30e23
font_01_sfnt_off0000f34f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF34F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010b66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B66 10876 bytes
SHA-256: 0d8c77c90b9654e0f3b603c90d4f80e8fb541294913260c29820881fdc6ba366