Malicious PDF — malware analysis report

Static analysis result for SHA-256 661b73d0bf40470e…

MALICIOUS

PDF

86.3 KB Created: 2021-07-08 04:49:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 0c9d5715fd9bc9c9dda47bfd0d790b0a SHA-1: 6ed976a5e9fe085d1b163039d4a6b0480f7f1731 SHA-256: 661b73d0bf40470ebeedc863ac0d5d9b5189e2417305a3cdd3b12b5bc9a0f058
176 Risk Score

Malware Insights

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

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains a link farm pointing to multiple compromised WordPress upload storage locations, suggesting an attempt to host malicious content or phishing pages. The presence of numerous links on disposable hosting and the use of UTM parameters further indicate a malicious intent to distribute or phish.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9848

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) or Microsoft license-boilerplate documents that carry no urgency or charge/dispute escalation.
  • 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://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608a7f965f374---59369709009.pdf In PDF document text
    • https://parokisantolukas.org/Uploads/userfiles/files/82003257629.pdfIn PDF document text
    • http://www.atrium-tuiles.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609156fd33751---61457933626.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16088087e41250---95198306411.pdfIn PDF document text
    • https://www.coconutlodge.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d3ed1918817---27176901797.pdfIn PDF document text
    • http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160823b83e8351---maxasajuverobor.pdfIn PDF document text
    • https://mmagame.com/userfiles/file/19321015620.pdfIn PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160a7aeedc5f5b---dagebazuludab.pdfIn PDF document text
    • http://moveisgarciadigital.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160869ed52ee3b---mafelaje.pdfIn PDF document text
    • https://kovtec.pl/eurostyl/photos/file/zusini.pdfIn PDF document text
    • https://catbasailing.com/upload/fck/file/sukanimomibas.pdfIn PDF document text
    • http://herodumpsterrental.com/wp-content/plugins/super-forms/uploads/php/files/7d989e51bf3cfdd3eb5275799a58afb7/givosopemepir.pdfIn PDF document text
    • http://anhuizpyy.com/upload_fck/file/2021-4-29/20210429101230562642.pdfIn PDF document text
    • https://wecafephuket.com/wp-content/plugins/super-forms/uploads/php/files/f1v0lg83q9fgeqlfbpe86jscrc/kovukuxufipugirezukepo.pdfIn PDF document text
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a85a004ea73---pipazodita.pdfIn PDF document text
    • https://pensiuneavalentina.ro/app/webroot/file/giludazivubugatunetimal.pdfIn PDF document text
    • http://aristosaigonhotel.vn/uploads/files/zuzokes.pdfIn PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/dfb01bf4d4c94304a267bceb38acf1c7/47535545717.pdfIn PDF document text
    • https://torbay.ru/images/uploads/file/boguxakobizaludikebeb.pdfIn PDF document text
    • http://vansuloi.com/uploads/userfiles/file/29742052033.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/cb5aa77ek67143usa6pdmq16ij/49523558569.pdfIn PDF document text
    • https://palet-school.com/files/files/puxamivajinumobafupofeg.pdfIn PDF document text
    • https://precisionautoandac.com/wp-content/plugins/super-forms/uploads/php/files/f557a9dce4f4c338b8bcf5d29bf8dc5d/13719037087.pdfIn PDF document text
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/16080e5beec79d---bimaresekumegamokeb.pdfIn PDF document text
    • https://antoinepanau.com/wp-content/plugins/super-forms/uploads/php/files/df0d5dba2c13027f3dd5447aa0cb1a25/23675546299.pdfIn PDF document text
    • http://thefutureofgolf.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1609b0bf728efd---27733348911.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=all+souls+discovery+of+witchesPDF 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_off0000efae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFAE 10656 bytes
SHA-256: f0ce853687ef1ea028a8bf96300d9b481d530c22400b01e76cd371388853b6a9
font_01_sfnt_off00010855.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10855 16828 bytes
SHA-256: 7f09888f448ee80fb6a1e0665697542672a79b327a724b8320030eae7b361be0
font_02_sfnt_off000133bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x133BD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1