Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c2fa248a2df1437…

MALICIOUS

PDF

83.7 KB Created: 2021-09-18 05:55:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 6bf2d02fbe7d8929e9374f09fdfd134c SHA-1: 16508ec8f1cfdd57b7d6ecf2446b750b6c654214 SHA-256: 4c2fa248a2df14375c19fcb6f38dc03e80a0a349b4dd2c9483e7ccdc8df4bdfb
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which are hosted on disposable domains or compromised WordPress sites, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. The presence of external URI heuristics and link farm indicators points towards a spearphishing attachment as the likely initial access vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://medvor.ru/uplcv?utm_term=free+frp+unlock+service PDF link annotation
    • http://toroisg.com/public/images/files/27528754098.pdfIn PDF document text
    • http://sicompk.com/survey/userfiles/files/10323800544.pdfIn PDF document text
    • https://spyboarcams.com/files/15021848500.pdfIn PDF document text
    • http://dlabiura.kbo.pl/ckfinder/userfiles/files/pemutezasa.pdfIn PDF document text
    • https://csp-pub.com/stockages/files/85345315189.pdfIn PDF document text
    • http://aftp.bg/userfiles/file/borafazigoxirudugurewi.pdfIn PDF document text
    • http://abwlanham.com/uploads/files/gajofaxuwab.pdfIn PDF document text
    • https://shindah.com/images/ckeditor_img/files/36945564463.pdfIn PDF document text
    • https://djecijagarderoba.me/userfiles/file/67108204224.pdfIn PDF document text
    • http://feminella.ro/upload/fck/jikijibebev.pdfIn PDF document text
    • http://objetivovender.com/wp-content/plugins/formcraft/file-upload/server/content/files/161328a6630739---92460494943.pdfIn PDF document text
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614122e7081cc---63698611285.pdfIn PDF document text
    • http://vucert.vn/uploads/files/39563630176.pdfIn PDF document text
    • https://xn--fct5g39pjpo.tw/upload/leakstop/files/letig.pdfIn PDF document text
    • https://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/161402bc96b7ae---17031429931.pdfIn PDF document text
    • https://baoholaodong24.com/userfiles/file/14947483772.pdfIn PDF document text
    • https://satbietthu.com/luutru/files/6754129333.pdfIn PDF document text
    • https://www.popcaffe.it/wp-content/plugins/super-forms/uploads/php/files/ca80b8c9bd91ae472e049a1f4cb22edd/66517337679.pdfIn PDF document text
    • http://yonseri.org/userfiles/files/nelubelutubeda.pdfIn PDF document text
    • http://laduses.nl/image/file/83825125790.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/708a7593bda0085793769af2a3e0a4dd/ridevedoxorisebipoko.pdfIn PDF document text
    • https://cualuoihoanmy.com/uploads/userfiles/file/kezonit.pdfIn PDF document text
    • https://kalashad.com/userfiles/file/23695388423.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_off0000e1f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1F2 10448 bytes
SHA-256: f024c785755607bdb626b6a785fc9f978c3c711a9210b33564cd555aaa472aeb
font_01_sfnt_off0000f9bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9BF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000111d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111D1 17988 bytes
SHA-256: ad20dd883322b0039658b9227e7d4f53b07fc50b97bcb578b0891aa0a800696c