Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef4ccd473497b0c2…

MALICIOUS

PDF

84.1 KB Created: 2021-09-13 05:19:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 8534143954dc4f0eac7e2350bba0ab5d SHA-1: eba62d9de983688a415899c8db2073e049824f8f SHA-256: ef4ccd473497b0c207a91ec1757a93c455695c4960e2e64fd4e6c1b25e3bc467
156 Risk Score

Malware Insights

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

The PDF file contains numerous links pointing to compromised websites, which in turn host other PDF files. This structure suggests a link farm designed to distribute malicious content, likely for phishing or malware delivery. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

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://forter.vn/hinhanh/file/vuxonigawuzukurijapajatud.pdf In PDF document text
    • https://k9-warrior.com/wp-content/plugins/super-forms/uploads/php/files/ucu7g828ql7ccmmq0jpg5588l1/setemitosiwazi.pdfIn PDF document text
    • http://travelci.ru/ckfinder/userfiles/files/74090253286.pdfIn PDF document text
    • http://soluzionebenessere.eu/userfiles/files/28183676910.pdfIn PDF document text
    • http://www.sintsprev-ms.org.br/ckfinder/userfiles/files/31837303870.pdfIn PDF document text
    • https://leonardscopysystems.com/home/leonards/public_html/ckfinder/userfiles/files/zeresanipugitalagifetefu.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/161347a7c99b12---xisos.pdfIn PDF document text
    • http://chingyi.tw/userfiles/files/57180420660.pdfIn PDF document text
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e6389b6d7a---93380357963.pdfIn PDF document text
    • http://isystemlab.com/admin/ckfinder/userfiles/files/vunajekefexigazawo.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/vatuwinerimutugexexokazi.pdfIn PDF document text
    • https://hondaotohaiphong.vn/upload/files/mipigegofesomak.pdfIn PDF document text
    • http://limobebe.com/userfiles/files/pokigalojufezo.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161374e18d59f5---60658186999.pdfIn PDF document text
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/211f7a1357cea11e086bfea5475aaf11/duwugarejasojag.pdfIn PDF document text
    • http://animalscipublisher.com/files/upfiles/file/40523029265.pdfIn PDF document text
    • https://yk-tech.com.tw/ckfinder/uploads/ckfiles/files/fulesofezuselog.pdfIn PDF document text
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613145c07d648---wefijedadodezutulipupug.pdfIn PDF document text
    • https://marblobath.com/app/webroot/img/files/60847105920.pdfIn PDF document text
    • https://ntct-dz.com/ckfinder/userfiles/files/terumupofapobanibe.pdfIn PDF document text
    • https://cplastik.net/data/cms/file/7328237650.pdfIn PDF document text
    • http://shuimotongyuan.com/userfiles/file/36719222702.pdfIn PDF document text
    • https://www.loisirs-auto-occasion.fr/ckfinder/userfiles/files/86853612806.pdfIn PDF document text
    • https://ketgate.eu/wp-content/plugins/super-forms/uploads/php/files/4a0e1c6711db4d23abfe138b3d1c18e8/41307105256.pdfIn PDF document text
    • https://sodigital.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613e8b1cdd166---totuniribelaruda.pdfIn PDF document text
    • https://tlkingatlan.hu/kepek/other/file/36729732975.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=android+tv+box+change+launcherPDF 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_off0000e46a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE46A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fc7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC7C 17584 bytes
SHA-256: 5d52f39eaecb0c32388beb8209bfd118175297705bdf5d40664447fbf89b188f
font_02_sfnt_off00012a0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A0B 10868 bytes
SHA-256: c208a6fa2a0451ce4a96836c40515180ea6a4e823db8b6e206022bd2d3df076c