Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a9be4f958dcf384…

MALICIOUS

PDF

75.7 KB Created: 2021-09-01 09:26:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 67b8017f01659d2ba3883dd37b50cf36 SHA-1: 5349e2cb591c291256acd6d3f7dfa10ada79290e SHA-256: 5a9be4f958dcf384f1be05c8a1352c9901bdf44d33b51166c9ce28c34423d0ab
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it functions as a link farm on potentially compromised or disposable hosting. The presence of embedded JavaScript suggests an attempt to execute malicious code or redirect users to phishing sites. The numerous extracted URLs, many pointing to PDF files hosted on various domains, reinforce the link farm and potential phishing lure attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://bjjewels.net/nbloom/fckuploads/file/77196712913.pdf In PDF document text
    • http://superfishinglewood.com/uploads/files/gowafozi.pdfIn PDF document text
    • http://bpabv.nl/uploadfiles/file/lemem.pdfIn PDF document text
    • https://ckmusicdesign.nl/userfiles/file/penebetetevoxiba.pdfIn PDF document text
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be298b22847---78711524544.pdfIn PDF document text
    • https://leunamgroup.com/wp-content/plugins/super-forms/uploads/php/files/e290724f08ec2b7500e5d6c0aec62977/55309686043.pdfIn PDF document text
    • http://studiotecnicodavico.eu/userfiles/files/tawixofarinamik.pdfIn PDF document text
    • https://accu-split.com/userfiles/files/64442938654.pdfIn PDF document text
    • http://vikohasanfiber.com/upload/files/rokagowikefefabajuwed.pdfIn PDF document text
    • http://havefuntogether.com/image/upload/File/teluju.pdfIn PDF document text
    • http://www.bestlifepolicy.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160939f5414765---pusirupurinanetotigaf.pdfIn PDF document text
    • http://ssanadia.in/userfiles/file/41928108587.pdfIn PDF document text
    • http://doudou.tw/userfiles/files/xeluxisaxijak.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/0e365c795c58cc1c540f119ec35b8553/zekofopetenukalejopubu.pdfIn PDF document text
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1606ce7e64152e---90657682953.pdfIn PDF document text
    • http://grupogmec.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d5c8da96b5---togoga.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1609458ed84255---34163041662.pdfIn PDF document text
    • http://lamelove-zakryti.cz/userfiles/file/kajulosuvepira.pdfIn PDF document text
    • http://1137.jp/app/webroot/js/ckfinder/userfiles/files/pifizemimalebusen.pdfIn PDF document text
    • http://zpb-maciejewski.pl/upload/fck/file/denepoguwuzazetikujaxo.pdfIn PDF document text
    • https://oykufestivali.com/ckfinder/userfiles/files/powajaludozuzaruj.pdfIn PDF document text
    • http://trungnguyenjsc.vn/uploads/image/files/lunubalitodul.pdfIn PDF document text
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/16088bc3fba1c3---30218288498.pdfIn PDF document text
    • https://www.alphaveneers.com/wp-content/plugins/super-forms/uploads/php/files/7d3f308a22140efe8df7b9cba5a23670/38818021088.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=once+upon+a+time+in+china+ii+1992PDF 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_off0000c2f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC2F7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000db0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB0E 10788 bytes
SHA-256: 8495f7f58401f63412656968c0715d1d4513fa649574a47cae0687b03455bc2c
font_02_sfnt_off0000f3d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3D6 17204 bytes
SHA-256: d5f6c1a07c43205b2d84afd3ce102a60fc224deab2b0764ec9100990d5e47278