Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c1f25538d57706b…

MALICIOUS

PDF

80.4 KB Created: 2021-09-07 21:51:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 52fb819ff5298a8d6377e9c604bdcc2a SHA-1: 507e9a6182edb525b290098761de0f7fd5fc46aa SHA-256: 8c1f25538d57706bda4e6ce985391588ada8240a887ee37c7a1af7740ea78ea4
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Numerous heuristics indicate the PDF functions as a link farm, directing users to various external websites, many of which are hosted on compromised or disposable domains. These links likely serve as lures for phishing attacks or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://cructi.ru/uplcv?utm_term=teste+de+ingl%C3%AAs+avan%C3%A7ado+com+gabarito+pdf PDF link annotation
    • http://merlegdoktor.hu/tmp/favevazokevubopirevogawu.pdfIn PDF document text
    • https://vgi-vn.vn/app/webroot/img/files/noxobuwileroxixamasele.pdfIn PDF document text
    • http://saringkarnwood.com/UserFiles/file/kogil.pdfIn PDF document text
    • http://fouladsazanco.com/Upload/file/nekomibonudina.pdfIn PDF document text
    • http://jiendurancecoaching.com/ckfinder/userfiles/files/30177283790.pdfIn PDF document text
    • https://photographerin.agency/wp-content/plugins/super-forms/uploads/php/files/c1es13ae1n3bi1hpj6lc2iqaa6/tobawakusunomurudanawelij.pdfIn PDF document text
    • http://fkhd.cz/data/img/dubiwopufa.pdfIn PDF document text
    • http://soundreaming.org/wp-content/plugins/super-forms/uploads/php/files/92b99b7a9db29cd4fd1e5ce47ac1a4ba/toxugimepet.pdfIn PDF document text
    • https://parquesanalbertohurtado.cl/ckfinder/userfiles/files/pixadivuvezibo.pdfIn PDF document text
    • https://journeypeople.cc/wp-content/plugins/super-forms/uploads/php/files/abf70f30dc2818ba65f0638cc841ac0e/13471244993.pdfIn PDF document text
    • http://studioguidobarbieri.it/userfiles/files/93288942267.pdfIn PDF document text
    • https://socialacademy.gr/wp-content/plugins/super-forms/uploads/php/files/1390b517bb01bc5f8ce18bf611804ce0/9412656136.pdfIn PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fb3aebe3e1f---25379888469.pdfIn PDF document text
    • http://kcde.kr/userfiles/file/latabuzuzekidinusiser.pdfIn PDF document text
    • http://alvit-bk.ru/userfiles/file/24349343072.pdfIn PDF document text
    • https://prikolnaya.com/wp-content/plugins/super-forms/uploads/php/files/67be985ae046b1e1152093d1f0cfe320/99868912055.pdfIn PDF document text
    • http://walthamclassof1985.com/clients/5/52/52060312c10aa816a718e90a19a6a7a1/File/pifiwo.pdfIn PDF document text
    • http://www.siscbolivia.com/admin/uploaded/fck/file/37060838029.pdfIn PDF document text
    • https://www.chartsunlimited.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/16079104b90396---62329365772.pdfIn PDF document text
    • https://balaji-technology.com/userfiles/file/16032858560.pdfIn PDF document text
    • http://signexpowholesale.com/project-new/christianbook/upload_images/file/44562914198.pdfIn PDF document text
    • https://arenda1s.ru/wp-content/plugins/super-forms/uploads/php/files/178b4f70f3a96934653f771cac5a0ade/nebagojafopifuwedurugix.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_off0000d343.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD343 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000eb5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB5A 11492 bytes
SHA-256: 4ffeda3599220bb6688c461c7270583fbcd369eb313af46d045595bb2256a884
font_02_sfnt_off00010583.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10583 18000 bytes
SHA-256: f619f40f59074527a5a5056c6f89c324a0a6a65734f5eb372398ae664bf96991

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