Malicious PDF — malware analysis report

Static analysis result for SHA-256 626289d1b3542b4f…

MALICIOUS

PDF

90.1 KB Created: 2021-06-27 11:33:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 8076f0b1451b619ebe2bbded23cb30b9 SHA-1: cdd223d2d2ba19438615419399e1c50bf3606cb4 SHA-256: 626289d1b3542b4fd4f32afe66f5e451b944d508668a9551a7a98de5f6fcc173
156 Risk Score

Malware Insights

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

The sample is identified as malicious by ClamAV and an ML classifier, indicating a high probability of malicious intent. It functions as a link farm, with numerous URLs pointing to compromised WordPress sites, likely serving as a lure for phishing or malware distribution. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, suggesting the document is designed to leverage SEO for traffic to these compromised hosts.

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://chcial.ru/uplcv?utm_term=asia+is+the+largest+continent PDF link annotation
    • https://hotelritariccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607534bd74d1a---26627237001.pdfIn PDF document text
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609135294e563---95546233190.pdfIn PDF document text
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085a21b8ed7e---vejekiwakedefolifuxo.pdfIn PDF document text
    • https://techson-cctv.com/upload/file/13246498426.pdfIn PDF document text
    • https://www.expoagrogto.com/wp-content/plugins/super-forms/uploads/php/files/rd9dsj6a28emj58p44adje1t12/51475947263.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/160c6999a3aba8---68309684875.pdfIn PDF document text
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/mejavag.pdfIn PDF document text
    • http://stellamaris.cz/userfiles/95577797244.pdfIn PDF document text
    • https://mmszke.hu/files/file/53515681004.pdfIn PDF document text
    • https://delcinfo.ru/img/files/files/60614725028.pdfIn PDF document text
    • https://marljivo.hr/UserFiles/files/xaxotejiw.pdfIn PDF document text
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/160947c68470df---dotaperulipikumud.pdfIn PDF document text
    • http://allmedicus.com/userfiles/file/78445376205.pdfIn PDF document text
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/tecsfm77r0q71hodh5ov987c15/46796002449.pdfIn PDF document text
    • https://www.medipratik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160794b6bf215e---bazofujamejitexiralo.pdfIn PDF document text
    • https://goactive.hu/wp-content/plugins/super-forms/uploads/php/files/4fe7b1fc86395334fc405c3835ffd979/legipizafumakerijopowaj.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a1dcbb29fa1---97122648619.pdfIn PDF document text
    • http://php-lounge.de/userfiles/file/70679765313.pdfIn PDF document text
    • http://seoulsquare.com/userfiles/file/10960623807.pdfIn PDF document text
    • https://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7a41674ec5---24985112907.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/st6o7484s9v1teceiv4gjpdl31/tizodopopetepabedo.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/160892aeb2cf5e---zenujoxikutavupazi.pdfIn PDF document text
    • https://www.ccps.mx/wp-content/plugins/super-forms/uploads/php/files/5b4052511bc82131a735e3aeab9813d8/zoviweforojawodowarewev.pdfIn PDF document text
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607272adc2031---vasidita.pdfIn PDF document text
    • https://csom.cz/wp-content/plugins/super-forms/uploads/php/files/ec07f7143eeb964af295e3edce6a3a57/nofaxewutugukibovud.pdfIn PDF document text
    • https://himalayanwanderer.com/himalayan/userfiles/files/89653138823.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_off00010075.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10075 16636 bytes
SHA-256: d9280c80a1144f4e26c688941c2587736e30a4d60a39912d10069042c440748f
font_01_sfnt_off00012b3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B3E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00014355.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14355 10488 bytes
SHA-256: 7bb65467392fab945598f7b6a5dc19da2baaf9ca8f12c7d3c8f757062ae02ff4