Malicious PDF — malware analysis report

Static analysis result for SHA-256 934a8bb4c1b3fbca…

MALICIOUS

PDF

86.1 KB Created: 2021-09-18 11:13:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: f823bffa06113a2e2a780a751998d421 SHA-1: 5f91f02b552f5d3a729f0992ff77cac4f6288889 SHA-256: 934a8bb4c1b3fbca9a36d5eeaf8e34969bf4cab133e3c3508356935e312cf407
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as a malicious PDF by ML classifiers and ClamAV, indicating a phishing or trojan payload. It contains numerous embedded URLs, many pointing to disposable domains, suggesting a link farm or redirection mechanism to malicious sites. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a tactic to obscure the true destination. While no scripts were explicitly extracted, the nature of the embedded URLs and the detection signatures point towards an attack pattern involving user redirection to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://svenskafik.se/uploads/fckeditor/file/13893416757.pdf In PDF document text
    • https://0922.sproname.com/files/userfiles/files/wekikezerot.pdfIn PDF document text
    • http://mfahk.com/upload/files/81535712456.pdfIn PDF document text
    • https://myparrotfood.com/user_files/files/72430114757.pdfIn PDF document text
    • http://cesvil.it/filesUploads/file/8172610995.pdfIn PDF document text
    • http://1night2daytour.com/ckupload/files/fumiroguxebut.pdfIn PDF document text
    • https://kottayammedicalcollege.org/CMS/ckfinder/userfiles/files/90957199291.pdfIn PDF document text
    • http://flyingwedge.com/uploads/assets/file/dopuker.pdfIn PDF document text
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/16144267813f12---1886750751.pdfIn PDF document text
    • http://torgoborud.org/images/file/64121551536.pdfIn PDF document text
    • http://gocchame.vn/app/webroot/img/uploads/files/vibupemadazuzijudapomifig.pdfIn PDF document text
    • https://hgqq.hk/tony/churchofgod/ckfinder/userfiles/files/mamavikepujori.pdfIn PDF document text
    • http://thewesternmist.com/userfiles/file/13779115637.pdfIn PDF document text
    • https://barcelonacentremedic.cat/files/galeria/files/67626055416.pdfIn PDF document text
    • https://topinsolventa.ro/userfiles/file/vudonifiki.pdfIn PDF document text
    • https://sluganarodu.org/userfiles/files/rapofexosiwixose.pdfIn PDF document text
    • https://iagclaims.endataclaims.com/ModCoreFilesUploaded/file/80675834480.pdfIn PDF document text
    • https://motionslam.com/wp-content/plugins/super-forms/uploads/php/files/0db6a5680a426313fcd9611d3b76ef1d/76571488542.pdfIn PDF document text
    • http://mtsskzy.com/userfiles/file/tovugidikix.pdfIn PDF document text
    • http://zeci.nl/im/image/vasiwilizagov.pdfIn PDF document text
    • http://juncheng.tw/upload/files/vabegofepujotokilisa.pdfIn PDF document text
    • http://thanhnienxp.com/vietkiendo/upload/file/kujepotakoxitokidufes.pdfIn PDF document text
    • https://westhigienia.hu/editor_up/nosutuweve.pdfIn PDF document text
    • https://coolingrealestate.com/your-home-cleaner/FCKuploads/file/xuzagepazupi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=watch+onward+putlockerPDF 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_off0000e969.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE969 10620 bytes
SHA-256: d3db7384780427ce17aea31989e3a94dddc6775bdc94ce83b35b6ca070f32fff
font_01_sfnt_off000101b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101B6 18808 bytes
SHA-256: 3ca75f4233931b83f602b762793f78d1cd525829c04942a673df8ee6cb6b0c6f
font_02_sfnt_off000132a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x132A6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1