Malicious PDF — malware analysis report

Static analysis result for SHA-256 f10bb81f9a99be7f…

MALICIOUS

PDF

82.4 KB Created: 2021-09-17 06:25:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 8ffa6d90e3bfc62e446b52ba58fa7c91 SHA-1: 5e7c4fc77189870caf5055254e7f81eee2abe465 SHA-256: f10bb81f9a99be7f0d897096cdb4efe49f3aa425e3c49bd13ca50dd4d59cae22
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, with heuristics indicating it functions as a link farm. Several links point to compromised WordPress sites or disposable hosting, suggesting an attempt to lure users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://poexali.org/static/image/_u/system/files/82210934814.pdf In PDF document text
    • http://chinhsuasolieu.com/media/files/32453537585.pdfIn PDF document text
    • http://liweisteel.co.th/ckfinder/userfiles/files/43790071022.pdfIn PDF document text
    • http://sushistoryus.com/uploads/files/dixexuturaf.pdfIn PDF document text
    • https://phase1acoustics.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cf28e18a5a---dosukoso.pdfIn PDF document text
    • https://xtremefitksa.com/ckfinder/userfiles/files/80483800833.pdfIn PDF document text
    • http://yuanjiangchem.com/upload/files/98932399156.pdfIn PDF document text
    • https://susta.vn/userfiles/file/meripisabapivopubigepirux.pdfIn PDF document text
    • http://agavietnam.com/img/files/runuvitupomibu.pdfIn PDF document text
    • http://zhengfutz.com/v15/Upload/file/2021912114132831.pdfIn PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/oohh3fdvei3373b9om782ftsu2/pukifekurawof.pdfIn PDF document text
    • http://pfmconsulting.org/survey/userfiles/files/mirusixe.pdfIn PDF document text
    • http://kxzyjy.com/CKEdit/upload/files/75856656004.pdfIn PDF document text
    • http://17njl.com/userfiles/files/51432909385.pdfIn PDF document text
    • https://sharmtocairo.com/userfiles/files/49534186727.pdfIn PDF document text
    • https://psg66.ru/admin/ckfinder/userfiles/files/95500315501.pdfIn PDF document text
    • http://traditionsradio.com/wp-content/plugins/super-forms/uploads/php/files/1583f86f378aaa85b8efe992cd5df9a2/zesazijo.pdfIn PDF document text
    • https://jss-moms.si/upload/File/tagemalokoxazu.pdfIn PDF document text
    • http://www.me.ntou.edu.tw/ckfinder/userfiles/files/20210914_102950.pdfIn PDF document text
    • https://condicionamentofisico.com/arquivos/file/54907137339.pdfIn PDF document text
    • http://medical-1669.com/userfiles/files/99739308023.pdfIn PDF document text
    • http://nanoservice.cz/upload/file/80746799824.pdfIn PDF document text
    • http://j-club.eu/userfiles/file/5270979546.pdfIn PDF document text
    • http://piri-piri.pl/ckfinder/userfiles/files/gatejituxidodopopu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=popcorn+time+download+ios+freePDF 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_off0000de7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE7A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f68c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF68C 17404 bytes
SHA-256: 4aa0b75af579c2883b1bf2ea1d25a4274eaaa7a9cc2dbf6128e37fcacb940d04
font_02_sfnt_off00012341.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12341 10868 bytes
SHA-256: a716155aac438bbfcb22664d3dbaf6bf54b5decaf463a8b33befb0bd4bda7350