Malicious PDF — malware analysis report

Static analysis result for SHA-256 f81a11c683d2b41c…

MALICIOUS

PDF

110.4 KB Created: 2021-07-03 18:03:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: b1eb752bb8334580d0fc9416c0228fc9 SHA-1: 34a31ae5969c9511e6c7410909506fa528b57f9c SHA-256: f81a11c683d2b41cab7d6e3ae5f732a8e40682b8759f67ac3648161d3d3ee7ff
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a link farm pointing to numerous compromised WordPress sites and disposable hosting domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded URLs suggest a tactic of using compromised infrastructure to host malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://paklya.su/design/img/upload/file/tuxujuroxuvamujebemalum.pdf In PDF document text
    • https://www.temsilcifirsatlari.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d2cbc1de58---62640139623.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1608e15f412598---90188065834.pdfIn PDF document text
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609054a09e9ad---43018857814.pdfIn PDF document text
    • https://patriot.ch/wp-content/plugins/super-forms/uploads/php/files/5gdbtrf8pscel1no3sbv2ms7tv/84525954748.pdfIn PDF document text
    • https://hartwellcook.com/wp-content/plugins/super-forms/uploads/php/files/1db8b1d164c660b883d57ff7f94cda1d/rojukisatikixapomowozodi.pdfIn PDF document text
    • https://wilsonbarrera.com/inicio/wp-content/plugins/formcraft/file-upload/server/content/files/160bb0dc2ee4a4---19592960456.pdfIn PDF document text
    • https://www.getfitcrew.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f0f56317d0---42265485611.pdfIn PDF document text
    • https://parokisantolukas.org/Uploads/userfiles/files/35853813967.pdfIn PDF document text
    • http://redwoodpwr.com/wp-content/plugins/super-forms/uploads/php/files/l66msktf02qkvc9sb78qpjkib2/zefaxuxun.pdfIn PDF document text
    • http://asalsold.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609fea7ccca36---nogezoxeronoleviju.pdfIn PDF document text
    • https://brusroom.com/wp-content/plugins/super-forms/uploads/php/files/6b679452d2f78fa20319a9d979551121/50648777310.pdfIn PDF document text
    • http://entone.es/wp-content/plugins/super-forms/uploads/php/files/13578b63aad5c951ed87ab01fdc496c1/80980606258.pdfIn PDF document text
    • https://arhometutor.com/userfiles/file/tinumok.pdfIn PDF document text
    • https://mattweidnerlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160910e7213d60---bodajifesedemugopi.pdfIn PDF document text
    • http://lohsclassof70.com/clients/3/31/31ca850ff086a58b81c8700e10a01852/File/81474472728.pdfIn PDF document text
    • https://skazkavdom.com/wp-content/plugins/super-forms/uploads/php/files/77e18ff3556f8276782f2d80ed6de773/zobezil.pdfIn PDF document text
    • https://www.limratechnologies.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b8b2a577c91---77009149943.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b8c0697af62---34068178478.pdfIn PDF document text
    • http://uekekb.ru/!upload/files/limivisenigipuru.pdfIn PDF document text
    • http://nutronicltd.com/userfiles/file/4313868233.pdfIn PDF document text
    • https://envida-nieuws.nl/bsb_website/upload_fck/file/34335308589.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=projectile+problems+with+solutionPDF 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

Related samples 8

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00014a61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14A61 18328 bytes
SHA-256: 3f14c036d2d1d8b06c09276b8c959fe7cfd936d7abc78f57511d86e801ab6d37
font_01_sfnt_off00017b50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17B50 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00019367.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19367 10932 bytes
SHA-256: 8dd1d81a7d881d077dc318982c890f1f277ebfcf863e7526ed0df1821367a030

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