Malicious PDF — malware analysis report

Static analysis result for SHA-256 51fc6453b4ed94ec…

MALICIOUS

PDF

74.6 KB Created: 2021-09-21 02:46:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 8da9a7c53fd43b141778a964d528ae6f SHA-1: 23864a549cc8a0f983c0612827c24a53be92f217 SHA-256: 51fc6453b4ed94ec2d1a1cfc3504c5c7d267ac7e7657fc0570d3f3dda7862ce1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a large number of embedded URLs, many of which point to compromised websites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of external URI heuristics and link farm indicators further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://pistant.ru/uplcv?utm_term=clear+browser+cache+android PDF link annotation
    • http://superazs.ru/images/news/file/6664513639.pdfIn PDF document text
    • http://cbestdesign.com/ckfinder/images_store/files/korikerivoso.pdfIn PDF document text
    • https://sergiomauri.com/images/file/62810959176.pdfIn PDF document text
    • http://getdol.com/page_data/file/54585569531.pdfIn PDF document text
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141189f8dd46---vogekuzad.pdfIn PDF document text
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613fc8050a71c---koxemojijo.pdfIn PDF document text
    • https://maximatrimony.com/ckfinder/userfiles/files/rasaxefelugirefox.pdfIn PDF document text
    • https://dbhattacharjee.com/ckfinder/userfiles/files/poruzanexorujoxeja.pdfIn PDF document text
    • http://plafondchauffant.fr/img/user/file/nalokisepawigesawuwow.pdfIn PDF document text
    • http://luchetti.it/userfiles/files/52638193888.pdfIn PDF document text
    • https://mauspro.net/upload/files/33931536533.pdfIn PDF document text
    • https://alatheir.com/atheirwsfiles/file/87068327624.pdfIn PDF document text
    • https://fleuriste79.fr/ckfinder/userfiles/files/dalux.pdfIn PDF document text
    • http://tw-jia.com/uploads/files/202109070624208757.pdfIn PDF document text
    • https://gitedu.in/ckfinder/userfiles/files/64523123478.pdfIn PDF document text
    • https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/14orlqgvrsqj2r15plo33ddf86/fixisunubarelumebip.pdfIn PDF document text
    • https://ihotel2b.com/upfiles/editor/files/73897823354.pdfIn PDF document text
    • http://turinimoti.com/assets/userfiles/file/kujuzofo.pdfIn PDF document text
    • http://e-menu.hu/editor_up/7128141948.pdfIn PDF document text
    • https://tl-systems.hu/files/files/dizetirotakus.pdfIn PDF document text
    • http://lumieretvie.com/userfiles/file/lojonuwosedilumevukepi.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_off0000c12c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC12C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d93e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD93E 16800 bytes
SHA-256: 4c21c3e305ceb9c2ba13c1f20093060ca8e5be540d7436d12525375ff3fb274f
font_02_sfnt_off00010473.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10473 10628 bytes
SHA-256: e7dc5a0e4c874255db1e5ee392d652023184dcaaa9cc47e32b3e6a37c8760a70