Malicious PDF — malware analysis report

Static analysis result for SHA-256 a553d0038b0c4eb2…

MALICIOUS

PDF

73.4 KB Created: 2021-06-12 23:23:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 85f87cf881ef00c1f1e479ed236030cb SHA-1: 2f5441934f268da01b6d4fe1780a0c3aa94ad2a3 SHA-256: a553d0038b0c4eb2730d522e4280389088dcf16f18eb80bc39b558f6db3a1a38
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The file contains numerous links pointing to compromised WordPress sites and disposable hosting, suggesting it's part of a link farm used for phishing or malware distribution. The embedded URLs and the heuristic findings strongly suggest the document is designed to redirect users to malicious sites, likely for credential harvesting or to download further malicious payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://crysiq.ru/uplcv?utm_term=hamlet+book+pdf PDF link annotation
    • https://autotrilogy.com/wp-content/plugins/super-forms/uploads/php/files/0202184d206fdfa054af52571a0e5828/15940377440.pdfIn PDF document text
    • https://morethancleaningservices.com/wp-content/plugins/super-forms/uploads/php/files/87b4539f044eb7cc0340dd4775744091/71510800698.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/k83f7k6n4goak0j0j2ajohm0v3/davoxisipaz.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/50f0a3f28afdd9373dc5d2b1314891b1/futokunuvagekug.pdfIn PDF document text
    • https://lsp.od.ua/wp-content/plugins/super-forms/uploads/php/files/2esvd7lpht2joedckeb12u1lk2/birakopakusaxu.pdfIn PDF document text
    • https://amalighting.com/wp-content/plugins/super-forms/uploads/php/files/454dcd091e87f7f6993f3f965a2f04db/zigafefuxawanu.pdfIn PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/447b207998b320ed976baa841fbbccc9/70352631687.pdfIn PDF document text
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16081f326dc00c---19174171033.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/73ec4c8d1c6863d490e2e95768d9a0b4/93397265486.pdfIn PDF document text
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160a817b8b2476---motozolakexob.pdfIn PDF document text
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/16089837ae6881---86447903605.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/o80q0uhntdvjk28jket12e4kjg/29314605682.pdfIn PDF document text
    • http://moon-villa123.com/CKEdit/upload/files/jijilipet.pdfIn PDF document text
    • http://cn-polylysine.com/d/files/maniragekugazanun.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e3cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3CB 5080 bytes
SHA-256: 7ab309b7bfb9268cfc55c6b6f361cbe5bf18e1f0e92b813723b972e961357952
font_01_sfnt_off0000f501.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF501 10736 bytes
SHA-256: a5ca76395a5e9e34434319f1e2db134abe89061415f7d28b3e42812aeacd099f