Malicious PDF — malware analysis report

Static analysis result for SHA-256 c19efcd03978c8dd…

MALICIOUS

PDF

76.4 KB Created: 2021-09-20 09:55:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: d1b93c72f87c478d765dd206268116c6 SHA-1: 73dcf2a16d144810947ced8283781f587db0a089 SHA-256: c19efcd03978c8ddbf14b687cac29c2a6eff081298c5d63c86179fc22b172fcc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress upload storage and other domains. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a pattern of using disposable hosting for these links, suggesting an attempt to obscure the final malicious destination. While no scripts were extracted, the structure and heuristics strongly suggest a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://moveisgarciadigital.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16134aaa922a52---89799577664.pdf In PDF document text
    • http://kozelskadm.ru/files/uploads/files/zefakasixilupa.pdfIn PDF document text
    • http://awkontrakt.pl/ckfinder/userfiles/files/24938250043.pdfIn PDF document text
    • http://vanhacollection.com/images/files/56537490641.pdfIn PDF document text
    • https://www.domosystem.gr/ckfinder/userfiles/files/jawuzurulin.pdfIn PDF document text
    • http://vijyaiprismcrm.com/userfiles/files/jajiwiziredopiput.pdfIn PDF document text
    • http://uslugi-ogrodnicze.pl/pliki/File/32307930124.pdfIn PDF document text
    • http://yey.uw52.com/upload/files/nadizodukisasisaresitanu.pdfIn PDF document text
    • https://reha.bg/content/upload/file/27529645862.pdfIn PDF document text
    • https://projekt-lesen.de/userfiles/file/84529791565.pdfIn PDF document text
    • http://wirheiraten.de/images/file/86474461819.pdfIn PDF document text
    • https://theshamrockpublecco.it/file/masomuzowexuzazovun.pdfIn PDF document text
    • https://kueapem.com/contents/files/lemalezi.pdfIn PDF document text
    • http://doctour.hu/uploads/ckfinder/userfiles/files/53243361489.pdfIn PDF document text
    • https://jkmart.net/FCKFiles/File/57047520586.pdfIn PDF document text
    • https://pottoka.info/files/galeria/files/17677179161.pdfIn PDF document text
    • https://prokoncept.hu/admin/blogfck/image/file/67447097015.pdfIn PDF document text
    • http://telekommarketing.com/firme_data/files/38672129109.pdfIn PDF document text
    • https://cfi-registration.amyhalter.com/buzzboxgift/img/userfiles/files/42240240552.pdfIn PDF document text
    • https://edgecs.com/documents/65679309920.pdfIn PDF document text
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/b7c7b5fbf31bd7bcf73d3a2cefbb1f68/jumasozesufe.pdfIn PDF document text
    • https://isleo.com/i_photos/file/mufuv.pdfIn PDF document text
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/584240a6f89170ce647c8aa3ee37e2b6/39671071744.pdfIn PDF document text
    • http://daehnfeldt.com/userfiles/file/mujilarudezimelunixis.pdfIn PDF document text
    • https://v-rshine.com/upload/images/files/4877472331.pdfIn PDF document text
    • http://violetstudio.in/userfiles/file/losavifokov.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=fabric+ui+componentsPDF 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_off0000c4b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4B9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dccb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCCB 17716 bytes
SHA-256: 62d7eab630f9f069d69f268b99716c655f56ee1e3f3f47648d3ecc50e6800f68
font_02_sfnt_off00010bc0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BC0 10708 bytes
SHA-256: aa0daa6905922a1f963ef82481771ab69d5e9b64984726b7586b886793abd0ee