Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c4f4430ff56a040…

MALICIOUS

PDF

80.3 KB Created: 2021-09-18 12:54:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 489d810e276cbccd2de08cc0c71a2b99 SHA-1: 9fb314e5d846b0a2860a51b5cc8f9185c46feaff SHA-256: 3c4f4430ff56a040c5548ede001461f2837ec2cabf7f691e4552fc340a8318ec
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs that function as a link farm, redirecting users to various disposable hosting sites, likely for phishing or malware distribution. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically flags this behavior, suggesting the PDF's primary purpose is to drive traffic to these malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://krisoc.ru/uplcv?utm_term=les+miserables+book+pdf PDF link annotation
    • https://pakianco.ir/data/image/uploads/news/files/66329929901.pdfIn PDF document text
    • https://zaragozadenoche.es/upload/files/66232595409.pdfIn PDF document text
    • https://singlespeed-switzerland.ch/userfiles/files/91952120154.pdfIn PDF document text
    • http://topliving.sk/userfiles/file/konowaxoxotu.pdfIn PDF document text
    • http://kustari.net/userfiles/file/25672307149.pdfIn PDF document text
    • http://poorclarescork.ie/images/zokigarumulumifutem.pdfIn PDF document text
    • https://helicopterleasingservices.com/userfiles/files/71523326522.pdfIn PDF document text
    • http://asvpp.fr/pdf/52329253881.pdfIn PDF document text
    • http://freeware-software-download.de/uploads/editor/file/34666369779.pdfIn PDF document text
    • https://cristalparkhotel.com/ckfinder/userfiles/files/93306755247.pdfIn PDF document text
    • http://dangkykinhdoanhkiengiang.com/upload/ck/files/40710628301.pdfIn PDF document text
    • http://lynxitservices.com/ckfinder/userfiles/files/73822935097.pdfIn PDF document text
    • http://handlpc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/nojejoziwefuresi.pdfIn PDF document text
    • https://pielinks.com/UserFiles/file/29192849008.pdfIn PDF document text
    • http://lawfirm.vn/MINH/user_files/file/xusuximu.pdfIn PDF document text
    • http://simkoongschool.com/uploads/editer/files/64654906789.pdfIn PDF document text
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1613524d1e2def---23241002839.pdfIn PDF document text
    • https://cambodiadriverservice.com/userfiles/file/52936632898.pdfIn PDF document text
    • http://lsphc.com/userfiles/file///foroludimujudobi.pdfIn PDF document text
    • http://hanhthien.net/uploads/file/50838608749.pdfIn PDF document text
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134fc562e746---zexofilelibomawije.pdfIn PDF document text
    • http://istihdamhaberleri.com/upload/ckfinder/files/54241535739.pdfIn PDF document text
    • http://chipmax.in/chipmax/ckfinder/userfiles/files/56324849110.pdfIn PDF document text
    • http://eachfun.com/ckfinder/userfiles/site_eachfun_com/files/kavasovenatabivafi.pdfIn PDF document text
    • https://djecijagarderoba.me/userfiles/file/tisanav.pdfIn PDF document text
    • http://aranykoronakft.hu/userfiles/file/67475816122.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_off0000d1a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1A8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e9bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9BF 10648 bytes
SHA-256: 68bae66058c0441710e5dc39b387c7b256bf3e224290904848056781899a55f7
font_02_sfnt_off000101d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101D7 18700 bytes
SHA-256: d92621032c3549e5a60cd28e97373e45aa64907da44a461f7e81c6f5bdee8715