Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1c35c80396ebb63…

MALICIOUS

PDF

87.1 KB Created: 2021-07-15 10:44:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 6ecb40b4122cb8e5c9cb3be9769f2f4c SHA-1: c2af6040917d2fa4da0b7d8b738da3be63bdee21 SHA-256: a1c35c80396ebb63d04207622c6599fa08b1272a4aadef7ba7e5fc69def42523
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains numerous links to external websites, many of which are hosted on compromised CMS platforms or appear to be part of a link farm. The embedded URLs and the heuristic findings suggest the document's primary purpose is to redirect users to potentially malicious or SEO-manipulated content.

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 https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/3acd3f8e54d2c18f4598fd2a981ccdb3/tubekajakuritixobusi.pdf In PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084fba2b7535---bamunixisawuw.pdfIn PDF document text
    • http://strategie-online.net/catalogue_dynamique/file/82387943887.pdfIn PDF document text
    • http://amazingindiaphotos.com/amazingindiaphotos//upload/fckimage/file/19726727389.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/160a65bee9a839---nejur.pdfIn PDF document text
    • http://flynewsletter.com/uploads/file/69864748316.pdfIn PDF document text
    • https://www.rowtheerne.com/wp-content/plugins/super-forms/uploads/php/files/46434d92e060f9637d2538265b35cae8/95387002618.pdfIn PDF document text
    • https://dongytueduc.com/wp-content/plugins/super-forms/uploads/php/files/roi0osjm8qrplog0d0fsehsdt1/lolorenufoxorufex.pdfIn PDF document text
    • http://ahcxdq.com/uploads/file/080824474386.pdfIn PDF document text
    • http://magyaringatlanadatbazis.hu/dev/_user/file/wesuguzolok.pdfIn PDF document text
    • http://primethailand.com/ckfinder/userfiles/files/vifomatanawodefepiwijux.pdfIn PDF document text
    • https://trongtrucsolution.com/uploads/files/37586032338.pdfIn PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dfd144c9d51---66359674514.pdfIn PDF document text
    • https://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bd1d4d0aa55---80790137169.pdfIn PDF document text
    • http://vitalenzyme.com/uploads/fckupload/file/nisorofotologe.pdfIn PDF document text
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160757489b7c5b---volojobarokebup.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160b5439534a76---fudukatijezozisasitirili.pdfIn PDF document text
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607856831095f---wuvudivomigukarud.pdfIn PDF document text
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16091b46aeb2d7---vunigese.pdfIn PDF document text
    • http://sp3siemianowice.pl/userFiles/files/90035124060.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c20a1b16747---tofevema.pdfIn PDF document text
    • https://digireg.it/upload/51545712849.pdfIn PDF document text
    • http://anhuizhkj.com/upload_fck/file/2021-5-30/20210530044400143397.pdfIn PDF document text
    • http://wmehoa.org/clients/d/df/dff1b85474dadb967ea0c40f6d5e37f8/File/53919891840.pdfIn PDF document text
    • https://fortlauderdale-carservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092f451bb299---jibozi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=new+electric+car+companyPDF 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_off0000f219.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF219 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010a30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A30 10544 bytes
SHA-256: f76d0eea158ea306f4e7e148a81c8ba301e96c58199a5790c101a9ee4943bf6c
font_02_sfnt_off0001223e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1223E 17192 bytes
SHA-256: 238062ccf78e8928c8a6147fb92d76b1bfd9bac0e65067e20d944a25e3c5ca9f