Malicious PDF — malware analysis report

Static analysis result for SHA-256 855ea176876c0056…

MALICIOUS

PDF

89.0 KB Created: 2021-06-26 07:58:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 755712b53c479b301bbe2ada11f1c559 SHA-1: 05ccbe1a278ca1a8ec67ef690c4e190fa985e3ae SHA-256: 855ea176876c0056dad1eeb55c352a75ee896f5d052f7a175a23be1e0849a679
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by multiple heuristics and a machine learning classifier, with ClamAV detecting it as Pdf.Phishing.Trojan. The PDF contains numerous external links, many pointing to compromised WordPress sites, suggesting a link farm or phishing lure. The presence of embedded URLs and the nature of the heuristics indicate an attempt to redirect users to malicious content, likely for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://crewmak.ru/uplcv?utm_term=closest+waterfall+to+me PDF link annotation
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160948b5a79c03---13496455975.pdfIn PDF document text
    • https://christembassybarking.org/wp-content/plugins/super-forms/uploads/php/files/f42df9db8223b0f40d477f32c7ecefef/lufok.pdfIn PDF document text
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b4bff79e729---17427801717.pdfIn PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/31nae3k6cdejdkqmt26j50t98e/56088198575.pdfIn PDF document text
    • https://www.lang-mayer.de/wp-content/plugins/formcraft/file-upload/server/content/files/160d3a7e98dfe8---vegupugenavezu.pdfIn PDF document text
    • http://nedirajtebosnu.net/userfiles/file/buminidix.pdfIn PDF document text
    • https://www.cittadelmiele.it/wp-content/plugins/super-forms/uploads/php/files/6f5391699c63998557174cd77add6230/56536348311.pdfIn PDF document text
    • http://przychodnia-felinskiego.pl/uploads/editor/file/kesufiwekitafez.pdfIn PDF document text
    • http://businessplan-capalpha.eu/mbp/upload/images/images/upload/ckfinder/400160741.pdfIn PDF document text
    • https://ehblending.com/wp-content/plugins/super-forms/uploads/php/files/10fe8c177ce514905bbe9e54357734b3/51990669104.pdfIn PDF document text
    • http://voszveszprem.hu/_user/file/fijezefugorodegororuk.pdfIn PDF document text
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608867997f585---jojevovufev.pdfIn PDF document text
    • http://eurekaelearning.com/upload/news/file/xelijonipuvixederosuma.pdfIn PDF document text
    • https://www.finestkindcharter.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e79523ceba---29931687617.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/160b984f4ac15d---xutejolapugozoturo.pdfIn PDF document text
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad833740b0b---35018307988.pdfIn PDF document text
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072cc00c209c---xafopakewomapanidobev.pdfIn PDF document text
    • https://avistravel.ro/userfiles/file/lesupujali.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/4l7ohfe66ijuv97lk809pppcpb/23134279011.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab9594e5108---bawerozada.pdfIn PDF document text
    • http://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d1d988c9a2---wulumirukeludasutalaruva.pdfIn PDF document text
    • https://oiweld.com/wp-content/plugins/super-forms/uploads/php/files/756f6c2efdecfe66f15e2649c7c13b79/nodovibogigusuxevesi.pdfIn PDF document text
    • http://aleeblog.com/wp-content/plugins/super-forms/uploads/php/files/rs8s3d60eqg4un5jajh5novc06/16459695037.pdfIn PDF document text
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/mvipncrvbg08esv36pebc2irs3/vosunuvasomus.pdfIn PDF document text
    • http://xn----8sbnbd9chja.xn--p1ai/userfiles/file/gonazofuwik.pdfIn PDF document text
    • https://ahi.com.ua/wp-content/plugins/super-forms/uploads/php/files/b559192c714b61040ab4dab71a7a2b23/44025855682.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_off0000f9cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9CD 17276 bytes
SHA-256: 8bc784dea221880e0700524668649e4ad3f3c9d2280cecd6ea9100e0d444cdd4
font_01_sfnt_off00012735.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12735 10296 bytes
SHA-256: 42b04535d2c2eed7a88fbeeb51313b015a31885d5c58a26e2d9b43d8bdb9154d
font_02_sfnt_off00013e94.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13E94 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1