Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4fe6ef6666b1042…

MALICIOUS

PDF

81.9 KB Created: 2021-09-14 15:01:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 611a09edaeffebdcfab30056ec5610a4 SHA-1: 0af50ee6d8dbc6e6fadc6334d0afdd07cb30e518 SHA-256: a4fe6ef6666b104269889c8743a7ba91088f6968b223720e94b82a197a851c35
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF containing numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicative of a link farm used for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were directly extracted, the PDF structure and URL patterns are consistent with malicious document delivery mechanisms.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

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=huji+cam+apk+download PDF link annotation
    • http://stphilomenaonline.org/userfiles/file/nalugefurewogikidukok.pdfIn PDF document text
    • http://www.web-globus.de/ckfinder/userfiles/files/67795775352.pdfIn PDF document text
    • http://jshanwoo.com/ckfinder/userfiles/files/kakofewaza.pdfIn PDF document text
    • http://nextlab-semi.com/files/fckeditor/file/sigapidimiwagudakudetiza.pdfIn PDF document text
    • https://stallion-international.com/userfiles/file/jiduvoboka.pdfIn PDF document text
    • http://kingspec.su/wp-content/plugins/super-forms/uploads/php/files/6p6tkooptfkd4jo510jn0a9ak4/fuvali.pdfIn PDF document text
    • http://xn----7sbab1bcaqplb0ccyi9d.xn--p1ai/files/file/48637524136.pdfIn PDF document text
    • http://medica-eg.com/userfiles/file/rilunogiz.pdfIn PDF document text
    • https://clinicscrm.com/img/files/90245195908.pdfIn PDF document text
    • https://fcr-fomentoconsumoerenda.com/uploads/files/43623696715.pdfIn PDF document text
    • http://antoniolescio.net/userfiles/files/62302305459.pdfIn PDF document text
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/16132994f34773---lezemafutavakiwo.pdfIn PDF document text
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/1613d2192c16af---80261778319.pdfIn PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/vitkqodn9fa8rvtffm4qnhlf72/68304998546.pdfIn PDF document text
    • http://njbeihang.com/uploadfile/file///2021091008022348.pdfIn PDF document text
    • http://kamerton.nl/clientfiles/11194118771.pdfIn PDF document text
    • http://www.alex-vasilkov.ru/images/wisdom/file/694109190.pdfIn PDF document text
    • http://khiconghoixuancong.com/Khicong/admin/userfiles/file/koburajogezopek.pdfIn PDF document text
    • http://dgjst.com/upfile/file/52189856497.pdfIn PDF document text
    • https://dotcomtravelegypt.com/userfiles/files/muzazojudefodezefugopin.pdfIn PDF document text
    • https://lazeo.nl/userfiles/file/87552315929.pdfIn PDF document text
    • https://bevasilicones.in/userfiles/file/naxaf.pdfIn PDF document text
    • https://khangle.vn/uploads/images/files/pabefozuvimiwevejakesi.pdfIn PDF document text
    • http://sola-brothers.com/userfiles/file/14820745282.pdfIn PDF document text
    • http://kemenyseprosiklos.hu/upload/file/nadawifamimezu.pdfIn PDF document text
    • http://austral-immo.com/userfiles/files/68196579265.pdfIn PDF document text
    • http://aweibel.com/Photo/file/94456288614.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_off0000dbdb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBDB 10576 bytes
SHA-256: 76f4e678102e0c437b0a49b0667cd526b03af9a13d7c924e0a8fe48328a65ac2
font_01_sfnt_off0000f3e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3E7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010bf9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BF9 17584 bytes
SHA-256: 3d5fc077cce00cc5ac3ab0fcd5d31fdba52ffb2cb55a12b7a91f3f37e88510bf