Malicious PDF — malware analysis report

Static analysis result for SHA-256 93c404a86779b0f8…

MALICIOUS

PDF

82.1 KB Created: 2021-09-06 11:06:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 49845da835476f045037684546bd638c SHA-1: 4c2283204714524602d31c457c9257a88c8588b5 SHA-256: 93c404a86779b0f84e12c7940a8032c9e29649e637aaa868880c038d088bc152
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1055.012 Process Injection T1204.002 Malicious File

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier, indicating malicious intent. It functions as a link farm, containing numerous URLs pointing to compromised WordPress sites and other domains, likely to host phishing pages or distribute further malware. The document body is heavily obfuscated and contains metadata indicating it was generated by wkhtmltopdf, a tool often used to create PDF versions of web pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://laborke.ru/uplcv?utm_term=daltonismo+em+pdf PDF link annotation
    • https://nicemexico.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a66a214cd96---24984506885.pdfIn PDF document text
    • https://endoaccessories.com/wp-content/plugins/super-forms/uploads/php/files/0kflo5mft7h1c6s64nr7t7ab0n/78734264700.pdfIn PDF document text
    • http://brodart01.com/wp-content/plugins/super-forms/uploads/php/files/065qvtiiulksprand6q7p121nj/nedikowoguwe.pdfIn PDF document text
    • http://berbun.com/user_img/file/finenusigoxuzoped.pdfIn PDF document text
    • https://remoteworkerclub.com/wp-content/plugins/super-forms/uploads/php/files/fb9004cebd62b1ebfa9a6304e81853af/51965731456.pdfIn PDF document text
    • http://alt-1c.ru/userfiles/file/8538164095.pdfIn PDF document text
    • https://graffitipaintstudio.com/wp-content/plugins/super-forms/uploads/php/files/91e3693f008cc957a5128ec7e0c58d57/31282043122.pdfIn PDF document text
    • http://portableandcool.com/files/files/53297149333.pdfIn PDF document text
    • https://wilocom.ro/ckfinder/userfiles/files/fuvulibavuzod.pdfIn PDF document text
    • https://livredart.com/ckfinder/userfiles/files/kirezavobufurikowewu.pdfIn PDF document text
    • http://havefuntogether.com/image/upload/File/derisok.pdfIn PDF document text
    • https://sportli.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160a9581a1ddda---juxenosunerevebube.pdfIn PDF document text
    • http://www.drop-lok.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078ad325d9e1---barujowijapezomuzir.pdfIn PDF document text
    • http://ganan10.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160d69ced68b26---keraleb.pdfIn PDF document text
    • https://foxtailmag.net/wp-content/plugins/super-forms/uploads/php/files/037598e51a37e9d72ef3728a5fd74ca5/ranomesamugevabix.pdfIn PDF document text
    • http://cuboni.com/uploadfile/hong202108290439011057.pdfIn PDF document text
    • http://hakkabrothers.com/userfiles/file///salasevibirub.pdfIn PDF document text
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/495a7473719399d1f2b279d98c055a3b/vefudikifibopolododoforeb.pdfIn PDF document text
    • https://asesoriagade.com/app/webroot/files/files/21286693250.pdfIn PDF document text
    • http://supair-lux.hu/ckfinder/userfiles/files/vemuvajad.pdfIn PDF document text
    • https://www.hagensmarketing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160744199f1dc5---rodubu.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f8d4867e5c---92594309237.pdfIn PDF document text
    • https://qualitycountscleaning.com/wp-content/plugins/super-forms/uploads/php/files/955fd458d3df17e46bd9eccc33b44120/90097710301.pdfIn PDF document text
    • http://goraku-sangyo.com/userfiles/file/25134101886.pdfIn PDF document text
    • https://webtraffic.ch/wp-content/plugins/super-forms/uploads/php/files/tbml4po7finmngikq06e7rn4n2/80347734382.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_off0000dd65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD65 17632 bytes
SHA-256: 44f40a183aecb525f10a9a47c87f2a961ddba75870001457c28b678587f946b5
font_01_sfnt_off00010b4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B4A 10560 bytes
SHA-256: 2c9b33b7ee3c664c0499895ee85e29835932dcd72d72dc64a35a7f7dff9a5788
font_02_sfnt_off00012354.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12354 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1