Malicious PDF — malware analysis report

Static analysis result for SHA-256 53290addc81e757e…

MALICIOUS

PDF

76.3 KB Created: 2021-07-16 18:28:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 6d0913d35f667bc87998f00a7c58c30a SHA-1: 1383f0863d1e188c3c805aad5500bca6364d10c4 SHA-256: 53290addc81e757eecbd3de4d72bfac0c78c1576f4b544f1211e542908717bd5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by multiple heuristics as malicious, including a link farm pointing to compromised CMS uploads and disposable hosting. The ML classifier and ClamAV also strongly indicated maliciousness. The document's structure suggests it is designed to host numerous links, likely to facilitate phishing attacks or distribute further malware, rather than containing readable content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://technok.cz/wp-content/plugins/super-forms/uploads/php/files/10c14138aca5065036fe7c9abe7c5f7f/kelajefakesipelegurub.pdf In PDF document text
    • http://divorcefinance.nl/uploads//file/69096894214.pdfIn PDF document text
    • http://geose.ru/userfiles/file/nakoluginakosapakuzorani.pdfIn PDF document text
    • http://at2apigroup3.com/contents//files/61703730188.pdfIn PDF document text
    • http://dhf-china.com/d/files/remigesewazibasipuxeli.pdfIn PDF document text
    • http://www.sport-konyv.hu/userfiles/file/77930885112.pdfIn PDF document text
    • https://webtraffic.ch/wp-content/plugins/super-forms/uploads/php/files/src11br5ogfl3i8ptmmq5gl60m/rubemupululege.pdfIn PDF document text
    • https://ckmandarin.com/uploads/80398103422.pdfIn PDF document text
    • http://skiflogistics.ru/userfiles/file/7859920088.pdfIn PDF document text
    • https://www.projectorrentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072d5cd8fda8---21811217195.pdfIn PDF document text
    • http://urbanconstructions.org/images/uploadedimages/file/nidafaduzakomovovenun.pdfIn PDF document text
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a76f7904ccf---xeruritilu.pdfIn PDF document text
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c26b7ed144a---60301860295.pdfIn PDF document text
    • http://sevimticaret.net/userfiles/file/74019999307.pdfIn PDF document text
    • https://beribuket.ru/wp-content/plugins/super-forms/uploads/php/files/76fa13ed9c2517e8f8dcacac88877203/14234360187.pdfIn PDF document text
    • https://1sis.com/wp-content/plugins/formcraft/file-upload/server/content/files/160865550074ed---50807786568.pdfIn PDF document text
    • http://subventionsbetrug.de/wp-content/plugins/super-forms/uploads/php/files/5iisc5g5hl63jsd2db83bp2o94/88176003951.pdfIn PDF document text
    • http://benthanhsgfarm.com/images/uploads/files/junigukatowawo.pdfIn PDF document text
    • http://masan315.net/board/imagefile/file/pelazukasibokefemuz.pdfIn PDF document text
    • http://www.masozilina.sk/ckfinder/userfiles/files/71195472708.pdfIn PDF document text
    • http://hmconcretemixingplant.ru/d/files/puwigerekema.pdfIn PDF document text
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160aa23423b982---wukavotazanume.pdfIn PDF document text
    • http://njnccualumni.com/clients/0/05/05b55d2c4c342460da0dc2f503861b12/File/43735732507.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=photo+merry+christmas+happy+new+yearPDF 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_off0000c383.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC383 18064 bytes
SHA-256: 4b0f4c10b8c60c88c37d72bb9ee6a3a872355ca711f67748031ec67a687fa68f
font_01_sfnt_off0000f2e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2E7 10792 bytes
SHA-256: 6db39ff1b8c8c272fcd4d8cbab06ab5c4658ac3477386d1010615ee87aba6ddb
font_02_sfnt_off00010bb7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BB7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1