Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b3730ed465927c8…

MALICIOUS

PDF

100.0 KB Created: 2021-08-03 09:54:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: f7f6e5c80a614b53931d97d366e075f1 SHA-1: 612619747d92528d4846e65ce75b3d99ee31a5b3 SHA-256: 8b3730ed465927c8a71b21d4591e41a169ca3f96a18686713b50af8a8ca34294
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised WordPress upload storage, suggesting it's designed to redirect users to other malicious sites. The presence of multiple unknown URLs further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9889

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 https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/16099cc6537756---60446337571.pdf In PDF document text
    • http://brandnewgoods.net/userfiles/file/52089517290.pdfIn PDF document text
    • http://zaun-produzent.de/userfiles/file/farezipul.pdfIn PDF document text
    • http://otoozevran.com/resimler/files/3431016682.pdfIn PDF document text
    • https://yuktiedu.com/wp-content/plugins/super-forms/uploads/php/files/3bd1f75ca6132329f033119dc53c86c4/98414243817.pdfIn PDF document text
    • http://www.urbanwaterways.info/files/rumotozemibofijonufi.pdfIn PDF document text
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/1609299b76a0b1---17719007448.pdfIn PDF document text
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160b63aa926c4d---mevuxi.pdfIn PDF document text
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16085248771b59---18172267192.pdfIn PDF document text
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/fa871ef6a7039e06094d765049327a36/bosifudasitazid.pdfIn PDF document text
    • http://vitanova-cattery.com/upload/file/zezewubexuba.pdfIn PDF document text
    • http://fmi.lu/userfiles/files/ligeripasamoni.pdfIn PDF document text
    • https://alkhairi.co.uk/wp-content/plugins/super-forms/uploads/php/files/8c0803a9d5f4a2c000a23f25132af1e8/zabof.pdfIn PDF document text
    • https://citronel.com/userfiles/files/jikoja.pdfIn PDF document text
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/6d547e246c8d65d9994362b4b39fff47/sugujupigepujozavoxal.pdfIn PDF document text
    • https://vildmarksjagt.dk/userfiles/file/47025505993.pdfIn PDF document text
    • https://ddshower.com/ckfinder/userfiles/files/tewemiv.pdfIn PDF document text
    • http://sip7.online/wp-content/plugins/super-forms/uploads/php/files/f451992332c7c2e58798d520fa16e0df/fobasanesidasisawewow.pdfIn PDF document text
    • http://www.realisthotel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8da89df800---rupuxaxujamukiwo.pdfIn PDF document text
    • http://hungthanhauto.com/luutru/files/mugik.pdfIn PDF document text
    • http://carrozzeriardue.it/userfiles/files/mulunifa.pdfIn PDF document text
    • http://deborahmayerlawoffices.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/37017375504.pdfIn PDF document text
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c28ec9a63df---pipow.pdfIn PDF document text
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160765373f3300---84202133125.pdfIn PDF document text
    • http://thebankcardservices.com/uploads/files/zagozama.pdfIn PDF document text
    • http://sh8ke.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607de2e1352fb---89428126376.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=the+cure+bloodflowers+album+coverPDF 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_off000122c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122C3 10804 bytes
SHA-256: efdd183d51fcc0ed65b417eb2ef7da4c197462f3372b98ea5d87cfed3a240acb
font_01_sfnt_off00013bc0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13BC0 17332 bytes
SHA-256: 03ee671b57ead2fe8c59a4c4262c58050e28d54c218837f990fabe467571b2c1
font_02_sfnt_off000168bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x168BD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1