Malicious PDF — malware analysis report

Static analysis result for SHA-256 66ef828ec3ce75a7…

MALICIOUS

PDF

75.4 KB Created: 2021-09-17 18:44:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: b51a2cd997f6daf86aeb8d8e3120d665 SHA-1: 7979576b79f8eb498cc18d1dd45e5ad63f65c0a2 SHA-256: 66ef828ec3ce75a72e073169d01beee09fe908360dd3740de37a61c316ab0ee4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://splogservice.ru/content/files/tiwuxos.pdf In PDF document text
    • http://harckocsik.hu/userfiles/file/lamutil.pdfIn PDF document text
    • https://drosamahetta.com/userfiles/file/runegezulir.pdfIn PDF document text
    • https://www.acptechnologies.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cff782280e---73333211688.pdfIn PDF document text
    • http://skpizzasubs.com/uploads/files/41933547770.pdfIn PDF document text
    • https://grandhotelbulgaria.com/userfiles/file/maranisezukukopo.pdfIn PDF document text
    • http://wajl.net/img/file/2021910195147.pdfIn PDF document text
    • http://crescentcarpets.com/userfiles/file/tupeduzuzifanuvuwajod.pdfIn PDF document text
    • http://mh-gartengestaltung.de/userfiles/file/71559263698.pdfIn PDF document text
    • http://trendstyleimage.com/uploads/ckfinder/userfiles/files/60841931110.pdfIn PDF document text
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/161332071bdc0b---63532560412.pdfIn PDF document text
    • http://strahyi.ru/images/file/13588416736.pdfIn PDF document text
    • https://microfocus-realize2020mea.com/wp-content/plugins/super-forms/uploads/php/files/969dff2f974d1baef08d0066bd768e84/98025444791.pdfIn PDF document text
    • http://www.belladermeestetica.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613145c37aac1---masisat.pdfIn PDF document text
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613be43c2c860---luvetinivazomafidorem.pdfIn PDF document text
    • http://shqinze.net/admin/upimg/file///79350994190.pdfIn PDF document text
    • https://mimpishio2bet.com/contents/files/vadule.pdfIn PDF document text
    • https://rhdplumbing.com/wp-content/plugins/super-forms/uploads/php/files/9e99b1e21859176efb532c915ff4e412/32399948007.pdfIn PDF document text
    • https://dorfadvertising.com/ckfinder/userfiles/files/8236486890.pdfIn PDF document text
    • http://www.thunderesp.com/ckfinder/ckfinder.htmlfiles/98140288533.pdfIn PDF document text
    • http://orthodoxvaidikasanghom.org/userfiles/file/99046138064.pdfIn PDF document text
    • http://goldenteriyaki.com/uploads/files/60270572920.pdfIn PDF document text
    • http://gazosilikatnn.ru/uploads/files/pobox.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=how+to+have+robux+freePDF 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_off0000c3c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC3C9 17180 bytes
SHA-256: 716ab14fc65fec49f9c9e8c2acc1059aa5d552d111511ca1da91183069f0418b
font_01_sfnt_off0000f05e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF05E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010875.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10875 10384 bytes
SHA-256: c4de6eef015476ef66ca0fc4eaff9cf3465bcff43cd4f1f7f79e1a0f85178ac1