Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8f2e83f38b15193…

MALICIOUS

PDF

77.2 KB Created: 2021-09-05 03:26:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: e201ac2795710b22c163407b5706cd52 SHA-1: 069029474fb01834b88cfa8a6fbb2629aaf11447 SHA-256: c8f2e83f38b151938b755f9f7f97c75074afe659f533fdd4a121ffe528f9878b
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous URLs pointing to external sites, some hosted on compromised CMS uploads. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure suggests an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://lombardpruszkow.pl/local/userfiles/file/38128995778.pdf In PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160afe271a4bee---xurowegepozajokanovag.pdfIn PDF document text
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab9169e1222---39577617041.pdfIn PDF document text
    • http://cdseoulps.com/uploadfile/fckeditor/file/90059693667.pdfIn PDF document text
    • http://atlantichomeportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608445ede7b14---bugademu.pdfIn PDF document text
    • http://myflora888.com/ck_files/files/71422089426.pdfIn PDF document text
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/a33657deb1f07494dc56bd58e931a412/lipelipogarexezeronomo.pdfIn PDF document text
    • http://tencanpowder.com/d/files/65088605920.pdfIn PDF document text
    • http://sjar-tech.com/uploadfile/file///2021071303484846.pdfIn PDF document text
    • https://attack.lt/images/files/gogufuv.pdfIn PDF document text
    • https://rescue.bg/wp-content/plugins/formcraft/file-upload/server/content/files/16098b55830998---60412186071.pdfIn PDF document text
    • https://tuvanthietke13-5.com/webroot/img/files/47339587942.pdfIn PDF document text
    • http://tsg-vaganovskoe.ru/ckfinder/userfiles/files/97896081537.pdfIn PDF document text
    • http://lamorenj.com/userfiles/files/betaj.pdfIn PDF document text
    • https://www.ideaklinikankara.com/wp-content/plugins/formcraft/file-upload/server/content/files/160805ae5bd665---15926698486.pdfIn PDF document text
    • https://autoschiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608187e7d3fa3---devabotijaj.pdfIn PDF document text
    • https://stvorki.ru/files/file/18157207320.pdfIn PDF document text
    • http://www.dadosefatos.net.br/wp-content/plugins/formcraft/file-upload/server/content/files/160724191d15e5---89618082726.pdfIn PDF document text
    • http://shield-in.com/userfiles/files/suleguse.pdfIn PDF document text
    • https://edoxmarketing.com/wp-content/plugins/super-forms/uploads/php/files/lfgjb6qsffh3rdp5vsj2mudmpt/18317179978.pdfIn PDF document text
    • https://connect.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/5f9c7ba77776b08ac256f6eb6c2edd88/15134050075.pdfIn PDF document text
    • http://karimeh.com/public/userfiles/file/balamimubukutizazaj.pdfIn PDF document text
    • http://campingwithconvenience.com/files/files/46316959098.pdfIn PDF document text
    • http://i-dron.cz/data/file/livewofudowikovoluwiwepax.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=ingenuity+baby+convertme+swing-2-seat+manualPDF 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_off0000c81b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC81B 16744 bytes
SHA-256: 82e5f7c6e02c1bc4daab07c34aa3e6511801367fe171572a01ea9d7a6c6e9b4a
font_01_sfnt_off0000f29f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF29F 11184 bytes
SHA-256: 65dc5cbbc8b371e30eacce13a07cbee52fa375824163249293af8f28de733a78
font_02_sfnt_off00010d03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D03 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1