Malicious PDF — malware analysis report

Static analysis result for SHA-256 a393b5b806c4e3f4…

MALICIOUS

PDF

86.5 KB Created: 2021-09-23 17:11:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 377ba41f102c31056539a16673d08ed2 SHA-1: c4148f80bd2d79f511cf4c57bc23cab158e25548 SHA-256: a393b5b806c4e3f4ac71180fdca73bb775ebaf9e8bf9af469fc424026ef16889
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious content. The heuristics identified the PDF as a link farm pointing to compromised WordPress uploads and disposable hosting, with numerous external URIs, suggesting an attempt to redirect users to malicious sites. The document body was unreadable, but the presence of many URLs and the nature of the heuristic firings strongly suggest a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://nomylo.ru/uplcv?utm_term=free+skins+fn PDF link annotation
    • http://laarakkers.com/ckfinder/userfiles/files/14520867697.pdfIn PDF document text
    • https://safetypadlocks.eu/eurostyl/photos/file/lozexetebatamizoxenisuni.pdfIn PDF document text
    • http://tongchangkj.com/uploadfile/file///2021092107522115.pdfIn PDF document text
    • https://vwb.mrv-educationservices.com/content_file/files/53378347644.pdfIn PDF document text
    • http://thecuriosityshot.com/67195072798.pdfIn PDF document text
    • https://delphin-restaurant.com/ckfinder/upload/files/waxafizilisegifagitox.pdfIn PDF document text
    • https://voicelux.ru/wp-content/plugins/super-forms/uploads/php/files/6dab88d88e486da182c3825fa2e05b8f/51590109358.pdfIn PDF document text
    • http://fasson.vip/images/editor/files/nafutatiwazulojugofapaje.pdfIn PDF document text
    • https://www.harnoordesigns.com/wp-content/plugins/super-forms/uploads/php/files/d8e14ca1b65e5866f2b9c85ce307723a/ritoxinepifoganivolegim.pdfIn PDF document text
    • https://eghamatyab.com/basefile/bainbookcom/files/20707919600.pdfIn PDF document text
    • http://wahluenfty.com/userfiles/95505783861.pdfIn PDF document text
    • http://scherzerpc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/diperelimulidisa.pdfIn PDF document text
    • https://pointswestliving.com/ckfinder/userfiles/files/88900546370.pdfIn PDF document text
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140b8ff2357e---vubafeguzikilu.pdfIn PDF document text
    • https://mkserwis.pl/userfiles/file/juwujiduvusuzomoxapu.pdfIn PDF document text
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/161401c1cf09c6---towarebo.pdfIn PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/16136cdfb65fe6---zoxotetimufekejodadotaf.pdfIn PDF document text
    • http://altelaw.com/uploads/image/file/37843130698.pdfIn PDF document text
    • http://xiangzhuan.tw/upload/files/14688535139.pdfIn PDF document text
    • https://carparts-fixture.com/file/file/puxitilog.pdfIn PDF document text
    • http://thienlongadv.com/upload/files/4902670759.pdfIn PDF document text
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614aef178a643---fasuz.pdfIn PDF document text
    • http://nomayaku.com/userfiles/file/35407612019.pdfIn PDF document text
    • http://aokisuper.com/ckfinder/userfiles/files/92075450472.pdfIn PDF document text
    • http://handinks.com/ckfinder/images_store/files/fomajetam.pdfIn PDF document text
    • 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_off0000ee90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE90 18604 bytes
SHA-256: fa057c1fe130d6dd0ac46ba4a8d44d8e78b0be53d6bca3647c8c3e203f5e281d
font_01_sfnt_off00011ed6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11ED6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000136ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136EC 9852 bytes
SHA-256: d8711fd9a4f856a77e7b1124ef159766d7179c6ef1adb8581e6e6e77ee364649