Malicious PDF — malware analysis report

Static analysis result for SHA-256 533fbefd70751cdf…

MALICIOUS

PDF

74.6 KB Created: 2021-06-25 16:02:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2026-06-05
MD5: df23d38ff183111608ca0770f1c78fd1 SHA-1: 3efbd181f7b6629620086f7b072b25a9f7b37fc3 SHA-256: 533fbefd70751cdff4c83b1189b473e6c07d4de85f0f6856fe2a985b6bc27253
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier, and it contains numerous links to external PDFs hosted on compromised WordPress sites. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a link farm structure, suggesting the primary purpose is to redirect users to potentially malicious content. No scripts were extracted, but the overall structure points to a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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 http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb7d927bc1---kijimezoj.pdf In PDF document text
    • http://fujiya-la.com/uploads/files/savakefoxotofo.pdfIn PDF document text
    • https://www.kasekimi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f7fe1ee155---kaxemew.pdfIn PDF document text
    • http://www.klimavill.com//data/editorfile/87587150732.pdfIn PDF document text
    • http://aprendanow.com/wp-content/plugins/super-forms/uploads/php/files/af7c0d035d6803fa720260beabffa7f6/52849760457.pdfIn PDF document text
    • http://www.miamiairportlimo.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b0d75e432ee---rusagekebo.pdfIn PDF document text
    • https://shared401k.com/wp-content/plugins/super-forms/uploads/php/files/6f83e4d55c7ed571514f664a126ae05b/18058492127.pdfIn PDF document text
    • http://quangcaosms.org/media/ftp/file/midojexege.pdfIn PDF document text
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160a8f804a743e---mapubuzimezimesazufolep.pdfIn PDF document text
    • https://ambientltg.com/wp-content/plugins/super-forms/uploads/php/files/9ea4d25f0a8c577980f132412916b879/89579558480.pdfIn PDF document text
    • http://www.deadclan.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160ac1406a024a---xiwufifonidogofutil.pdfIn PDF document text
    • http://retroldn.com/userfiles/file/suzupenivesoxusifuwono.pdfIn PDF document text
    • https://wilsonbarrera.com/inicio/wp-content/plugins/formcraft/file-upload/server/content/files/160926afb41915---vetufiwuta.pdfIn PDF document text
    • https://www.finestkindcharter.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607be0d5a8519---gusupid.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b1a8447ddaa---45820395311.pdfIn PDF document text
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071cfdf8f826---vudifiz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=i+just+wanna+wish+you+wellPDF 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_off0000c3c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC3C3 16344 bytes
SHA-256: 53c0e8a1966cc47d85ee568636b65acf1b0fcb87dde425712ac6052bd6a8ebd1
font_01_sfnt_off0000edf1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDF1 10488 bytes
SHA-256: 5b67a157c0d236877ef5b10036ba4f2124037a4049a73a5a7360902967a1760c
font_02_sfnt_off000105c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105C2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1