Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b31e7b4c30d9957…

MALICIOUS

PDF

118.4 KB Created: 2021-06-26 04:36:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: b4fb2e6e7348bae0a04dad4d28b8aab4 SHA-1: f0692bbb6b0fdd93bb39fcb80e232b55909509c7 SHA-256: 8b31e7b4c30d99578159bd648349893f90e67a700bb24a519f055d22afb58095
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised CMS upload directories, suggesting it's designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the link farm structure is a common tactic for initial access.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9639

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.chartsunlimited.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/160772810e8520---mebafamedugogezusepava.pdf In PDF document text
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16088284665603---48512017380.pdfIn PDF document text
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba28f368af9---78263767967.pdfIn PDF document text
    • http://alltechsro.cz/files/26512665923.pdfIn PDF document text
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad7e72bf6d5---xedowibilenovegurobalawer.pdfIn PDF document text
    • http://agcslohian.com/userfiles/file/11297720255.pdfIn PDF document text
    • https://argumentua.com/i/file/sotanimus.pdfIn PDF document text
    • https://brahmagnanam.org/fck_uploads/file/mawamolo.pdfIn PDF document text
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608510e6cfb32---rapuwomenobuzetedetopos.pdfIn PDF document text
    • https://vieclamhanoi247.com/upload/files/wimofokevasodexidetox.pdfIn PDF document text
    • http://28777886.com/Lpf/UPFILE/userfiles/files/51859115755.pdfIn PDF document text
    • http://zap-interactive.com/uploads/files/pulufebavimi.pdfIn PDF document text
    • https://forumhotel.by/wp-content/plugins/super-forms/uploads/php/files/6jjcvamfomc9ki64p4poak1vr0/diximusemaw.pdfIn PDF document text
    • http://rauvuonsach.com/images/uploads/files/roxedeborugomusi.pdfIn PDF document text
    • http://azizolace.cz/images/file/feropaxagekujoxuvosejuwim.pdfIn PDF document text
    • https://mosoptagro.ru/wp-content/plugins/super-forms/uploads/php/files/42cfab57e462f45abff83a808c9b7582/katowesimow.pdfIn PDF document text
    • http://arniestribu.com/campannas/file/muzajowe.pdfIn PDF document text
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16089d798ad45b---86849292553.pdfIn PDF document text
    • https://kede.org/userfiles/file/dawupegunuzelu.pdfIn PDF document text
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1608e35cf35350---febesoxovu.pdfIn PDF document text
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba1cfa0bb35---63077888518.pdfIn PDF document text
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/22jivvm84o9lb16vj199g57c81/pufegesijamurukalisox.pdfIn PDF document text
    • https://www.idahomedia.com/wp-content/plugins/super-forms/uploads/php/files/2dcba83483aa839cbc33fc53df06297b/dorasujalagagukuzatiso.pdfIn PDF document text
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607e046984475---rapozipepazimerivozol.pdfIn PDF document text
    • https://www.kunapak.com/wp-content/plugins/super-forms/uploads/php/files/435t2bsf34guj1hirhd7ihljso/sorameloputesaxuzilutu.pdfIn PDF document text
    • https://jdbailbonds.com/wp-content/plugins/super-forms/uploads/php/files/10eda85dc54a075bdce4ad17a42510b2/joduberukoladudo.pdfIn PDF document text
    • https://www.reliancecareuk.com/wp-content/plugins/super-forms/uploads/php/files/be2ee7167105acdfabe7575807fbaeb7/8321278560.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=class+6+maths+chapter+4+extra+questionsPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00015252.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15252 11264 bytes
SHA-256: a22ddb124b3298439db83702a14d5f1795d4e482f818c6308bb89fc83a1cc9bd
font_01_sfnt_off00016c9c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16C9C 18672 bytes
SHA-256: 26d0ede42b26e3990d92d8ae44715d1ba34e25e6d53ff2bdce368afc37639d00
font_02_sfnt_off00019e27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19E27 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_03_sfnt_off0001b638.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1B638 16088 bytes
SHA-256: 450eea5fc67953cc3bdc764260aa6f1739571c17331c9588074966c3dbef4c6c