Malicious PDF — malware analysis report

Static analysis result for SHA-256 4bb75259cada1358…

MALICIOUS

PDF

79.0 KB Created: 2021-09-22 09:54:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 3c72ba37a83be27ab381d445c7c67929 SHA-1: 31deba870428c46ed7e36a42582b112d5ff10169 SHA-256: 4bb75259cada13589fe983e207ccedd63237e76106c9c5bdada65d1026aa9327
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as a malicious PDF by ClamAV and an ML classifier. It contains numerous external URIs, with a high concentration of links on disposable hosting, indicating a link farm designed to redirect users. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically flags this behavior. While no scripts were explicitly extracted, the presence of external links suggests an attempt to lead users to malicious sites, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://allytemp.ru/uplcv?utm_term=cr+hack+version PDF link annotation
    • https://ivfnna.gr/wp-content/plugins/super-forms/uploads/php/files/3e8a52a319746b5a45928325fcc21333/didirogasemepojosema.pdfIn PDF document text
    • https://limberhurstgallery.com/imageuploads/file/nobowususapogadepafuxipi.pdfIn PDF document text
    • http://remaining-mc.de/userfiles/file/ganigepoxad.pdfIn PDF document text
    • https://hsiaoying.com/userfiles/file/parujuza.pdfIn PDF document text
    • http://www.mearesandassociatesllc.com/siteuploads/editorimg/file/fesir.pdfIn PDF document text
    • https://bdata.vn/upload/files/9174065216.pdfIn PDF document text
    • https://www.znackakvality.info/files/52634499730.pdfIn PDF document text
    • http://fred-robin.com/ckfinder/userfiles/files/vaneba.pdfIn PDF document text
    • http://www.accessibilite-salle-eau.com/ckfinder/userfiles/files/28407618457.pdfIn PDF document text
    • https://tomaszbizon.tomaszbizon.pl/web/uploads/files/50046174540.pdfIn PDF document text
    • http://sinocelltech.com/filespath/files/20210912113429.pdfIn PDF document text
    • http://855solution.com/htdocs/cljr/data/files/63751232683.pdfIn PDF document text
    • https://gkatsov.com/userfiles/file/43094526227.pdfIn PDF document text
    • http://yztools.com/images/upload/File/luxexipoxog.pdfIn PDF document text
    • https://huaku3c.tw/uploads/files/202109110547085365.pdfIn PDF document text
    • http://agapetown.net/ckfinder/userfiles/files/vetinigejepozutejikile.pdfIn PDF document text
    • https://mlbcsimleague.com/ckfinder/userfiles/files/pizilekuposugobat.pdfIn PDF document text
    • https://puntodeplacer.com/userfiles/file/rikekonufazudib.pdfIn PDF document text
    • http://greenglobepms.com/uploads/gakavinizatupibenij.pdfIn PDF document text
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/1612fcd7683490---javiluviloxoremuvatomi.pdfIn PDF document text
    • https://stichtingech.org/ckfinder/userfiles/files/rajeratunepumexi.pdfIn PDF document text
    • https://harmony.im/userfiles/file/5873567290.pdfIn PDF document text
    • http://jtg-antracyt.pl/files/file/pokorejuzedi.pdfIn PDF document text
    • http://szpk.hu/_user/file/38890476771.pdfIn PDF document text
    • https://montpellier-business-plan.com/mbp/upload/images/images/upload/ckfinder/jokadiw.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_off0000d197.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD197 17372 bytes
SHA-256: a0611ba821f75bedd5abe75095a41ce7ad1940bf29fdbea14051f162fbf5a4ef
font_01_sfnt_off0000fec5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEC5 10372 bytes
SHA-256: cf01a7436d978f12f74acc276d828808d3e87c0b37418aeb3b24a7391a139595
font_02_sfnt_off0001163f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1163F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1