Malicious PDF — malware analysis report

Static analysis result for SHA-256 413dbc9fef1dff16…

MALICIOUS

PDF

87.0 KB Created: 2021-07-05 14:43:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: a5179d40455c644028fd2b4849075819 SHA-1: 40b9c3c0f4a7235339be5ebeb9e5a32d584d0891 SHA-256: 413dbc9fef1dff16c3ecb68e816e0ef9c2ee10a6e5ffec3ba298002003e3f0ed
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories, indicating a link farm designed to host malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware delivery via these links. The document body is unreadable, but the heuristics and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://drukarnia-warszawa.pl/pliki/file/bojezidelamigediweto.pdf In PDF document text
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b5170f9c1c5---duratezirapijemedokawa.pdfIn PDF document text
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/160ac7d59bc03e---xisevabilebenisavojod.pdfIn PDF document text
    • https://prosegik.com/wp-content/plugins/super-forms/uploads/php/files/a0fe39b7eadeb9392335d96394c6c073/64812620155.pdfIn PDF document text
    • https://www.paparazzirestaurant.com.au/wp-content/plugins/super-forms/uploads/php/files/3a52d9e82fb8c4be298035cecb106b0f/fosogivasexefox.pdfIn PDF document text
    • http://qhs1978.com/clients/d/dd/dd8db5a278a7ad55a2ada34b8e38ebcc/File/moxoxepuvanozibovade.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083a50a2d636---30034687172.pdfIn PDF document text
    • http://toicodonlyson.com/uploads/files/sipow.pdfIn PDF document text
    • https://www.areatransfers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2795e1ee84---bidemogoxaxu.pdfIn PDF document text
    • http://winterwonderlandzundert.nl/uploadimages/files/lojomidadujawep.pdfIn PDF document text
    • http://bjzjygj.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/71082901199.pdfIn PDF document text
    • http://www.nowsingapore.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/160ca5cdeaac58---54593784855.pdfIn PDF document text
    • http://soundreaming.org/wp-content/plugins/super-forms/uploads/php/files/3190ca3ba0aac694c02b4a4e0ddc1a7b/nalusanuxuzeji.pdfIn PDF document text
    • http://lltsg.com/uploadfile/file///2021053012475321.pdfIn PDF document text
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a0a69b06f07---86955556791.pdfIn PDF document text
    • http://zdrowejaja.com/Upload/file/sivunezinirixufom.pdfIn PDF document text
    • http://umiyawoodworks.com/fckdb/userfiles/file/dokefefunupenematoz.pdfIn PDF document text
    • https://formapolis.it/wp-content/plugins/super-forms/uploads/php/files/cc35327f350d5a49ce18325fe00b5448/robazoronosik.pdfIn PDF document text
    • https://ecef-groupe.com/wp-content/plugins/super-forms/uploads/php/files/s9qro2kc92eg6a4ihhu4f16q57/panopipaxuxafibuterimubaf.pdfIn PDF document text
    • https://shared401k.com/wp-content/plugins/super-forms/uploads/php/files/d29251368daad01f28a1c0946d1984a5/reroxowagakogoxekumobajuk.pdfIn PDF document text
    • https://spectrumohio.com/wp-content/plugins/super-forms/uploads/php/files/2f02f652b2ea1bd3579183b01f8c1592/nusareje.pdfIn PDF document text
    • https://transcendenceit.com/wp-content/plugins/super-forms/uploads/php/files/b6c8dc19c49b5b16fde6fcb50e8558a2/84275779214.pdfIn PDF document text
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a8440165b27---medelodifovunenopiluwefa.pdfIn PDF document text
    • http://hzjksj.com/images/upload/File/fugoxowajinibipip.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=two+ways+to+belong+in+america+compare+and+contrastPDF link annotation
    • https://sharpspringwww.kinsta.cloud/wp-content/plugins/super-forms/uploads/php/files/347ff8ca84a86dd24e395adcec19f075/gejuwopajugujuvebepel.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_off0000f01d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF01D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001082f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1082F 17088 bytes
SHA-256: ede694f87bef7518003ecf4d0a707ed33f84a7991383291d4d55334b5d7b6577
font_02_sfnt_off0001346c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1346C 11160 bytes
SHA-256: 930cf00e96204439c67a360d7e43929d9d6722dea35e9c03e68db8e5d01b3881