Malicious PDF — malware analysis report

Static analysis result for SHA-256 18c5a4f1df82392d…

MALICIOUS

PDF

84.5 KB Created: 2021-09-19 03:22:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: f6b81d0c9e8c6640e351114d78083129 SHA-1: 586459f1ddb19e6c0581479a694cd990d03a8f58 SHA-256: 18c5a4f1df82392d0d78bbc326484e782a2b44693e5566528be8e1e37e2aed3c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links, many pointing to disposable hosting or compromised CMS uploads, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the heuristic findings and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://kabelkyaobuv.sk/editor_uploads/files/mexukafobixorenafolunegi.pdf In PDF document text
    • http://thingsantiquesla.com/userfiles/files/49795203346.pdfIn PDF document text
    • https://bbensonmft.com/wp-content/plugins/super-forms/uploads/php/files/9814890726bffcf23b43bbc9d9d64e39/32386171510.pdfIn PDF document text
    • http://beergolfers.com/blog/images/file/larimupoz.pdfIn PDF document text
    • http://apex-architect.ru/images/file/41000584161.pdfIn PDF document text
    • http://sakem.org/userfiles/files/xosasiwatedotonudazerer.pdfIn PDF document text
    • http://bolshunoff.ru/images/wysiwyg/file/17148983656.pdfIn PDF document text
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/161314768b0c51---15191723872.pdfIn PDF document text
    • http://savvyais.com/userfiles/file/98739533448.pdfIn PDF document text
    • http://veitali.com/upload/files/beramisopabotid.pdfIn PDF document text
    • http://rzn-house.ru/upload/file/rinosusaxuwinuniru.pdfIn PDF document text
    • https://liftsystems.ro/LiftFiles/file/64177758200.pdfIn PDF document text
    • http://dermatologomiguelgallego.com/miguel/fck/file/32756214618.pdfIn PDF document text
    • http://topup-fight.com/ckfinder/userfiles/files/gavomolelaw.pdfIn PDF document text
    • http://michaelwilliamslaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/xevewadeg.pdfIn PDF document text
    • http://thinhhoanggia.vn/Images_upload/files/19979282451.pdfIn PDF document text
    • http://twtime.com/uploads/files/202109011911147333.pdfIn PDF document text
    • http://thm-holding.ru/wp-content/plugins/super-forms/uploads/php/files/61f6ff40f96928db86a683f42decc57a/31245692425.pdfIn PDF document text
    • https://libertyrealestate.in/ckfinder/userfiles/files/24236948899.pdfIn PDF document text
    • http://tensoinox.com/userfiles/files/58479809188.pdfIn PDF document text
    • http://tentauto23.ru/ckfinder/userfiles/files/12425976225.pdfIn PDF document text
    • http://hzzxtl.com/UploadFile/file/20210906001055297.pdfIn PDF document text
    • http://kiuanai.com/userfiles/file/15856542746.pdfIn PDF document text
    • http://digitalpolicycouncil.org/imagenes/file/moxazilujopudu.pdfIn PDF document text
    • http://kant21.com/userData/board/file/20449340403.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=jcb+dozer+excavator+game+2019PDF 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_off0000e1bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1BD 18832 bytes
SHA-256: 2efca82b86012819c043f1618eede5bbc90a930e8f2a30299dd2c93251865460
font_01_sfnt_off0001124a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1124A 11124 bytes
SHA-256: a7eaace401a7ac5aed5f571f9c321c305c872174b71fb26797875b05f169e035
font_02_sfnt_off00012c48.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C48 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1