Malicious PDF — malware analysis report

Static analysis result for SHA-256 34b28d39345aaf72…

MALICIOUS

PDF

72.0 KB Created: 2021-09-17 02:47:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 1a6522ca98e4fc18d2b9e22c9764b983 SHA-1: 3518f2dbe0194ffa50934807a12a55ee85517672 SHA-256: 34b28d39345aaf7270500eb46fb4fa976ac20e62fda223980bb057aeedb83a79
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs that point to compromised CMS uploads and disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. No scripts were extracted, and the document body was unreadable, but the heuristic findings are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://pixomot.ru/uplcv?utm_term=arc+radius+angle+formula PDF link annotation
    • https://stotex.rs/files/70379302275.pdfIn PDF document text
    • http://recamonde.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16134e8d12e334---91352988785.pdfIn PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/1613ae6cec6c05---suzawinonuf.pdfIn PDF document text
    • https://norservis.info/files/files/kavet.pdfIn PDF document text
    • http://hndgyl.com/v15/Upload/file/2021917655561848.pdfIn PDF document text
    • http://husplaza.hu/editor_up/52130561622.pdfIn PDF document text
    • http://wojno-stal.pl/pliki/file/xusav.pdfIn PDF document text
    • http://krukaiart.com/userfiles/files/58444470393.pdfIn PDF document text
    • http://zlzljc.com/uploadfile/file///2021090709195892.pdfIn PDF document text
    • https://growlocals.com/wp-content/plugins/super-forms/uploads/php/files/1310f2ee06a974a3762820a897111157/kafigutegebowoxedekap.pdfIn PDF document text
    • http://manpukulivermore.com/uploads/files/bobomojibixilus.pdfIn PDF document text
    • http://cwesp.biz/upload/file/wekukijuvuxotatozewixifev.pdfIn PDF document text
    • http://aiswaryamatrimonials.com/fck_uploads/file/kosojivopewefisarodogeji.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/1613aec860a059---58600343621.pdfIn PDF document text
    • https://ezgoe.com/10005001208290177/ckfinder/userfiles/files/sobugo.pdfIn PDF document text
    • http://bcslaw.hu/admin/fck_upload/file/83499778163.pdfIn PDF document text
    • http://www.juniorcollege.cl/ckfinder/userfiles/files/28413312100.pdfIn PDF document text
    • http://gruppocinofilomarsalese.com/userfiles/files/poxaduxeji.pdfIn PDF document text
    • http://forti.in/userfiles/file/10011266725.pdfIn PDF document text
    • https://mosallaesf.ir/uploads/ck/files/wajipane.pdfIn PDF document text
    • https://nissanzorba.ro/ckeditor/ckfinder/userfiles/files/33410316196.pdfIn PDF document text
    • http://runwellconsulting.com/file/file/75831079664.pdfIn PDF document text
    • https://totalsewa.com/userfiles/file/dovotagogitititekamutowom.pdfIn PDF document text
    • https://www.tcf.gov.tr/ckfinder/userfiles/files/21145241999.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_off0000b86e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB86E 16076 bytes
SHA-256: 7310b312caf19db632e9908bb4ccd1efb528c8865c42813c14fd37bd4b490f2f
font_01_sfnt_off0000e19e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE19E 10800 bytes
SHA-256: 90a9cdc8d6748ff67e4dc39a15b785b2f226e3c3b9fba856a502f51b0a586d62
font_02_sfnt_off0000fa4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA4C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1