Malicious PDF — malware analysis report

Static analysis result for SHA-256 6ec3f60920bba1a1…

MALICIOUS

PDF

72.4 KB Created: 2021-09-30 16:20:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: bc7e3eeb569ac1402273c3104ad37dd6 SHA-1: a84c9ec1f77ed7bda44726c21cde08cf85fc6796 SHA-256: 6ec3f60920bba1a19d17796caeba1c1f6ad6175a075176d3da6806ff4497a430
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous external URLs, several of which point to compromised CMS upload storage. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The primary attack pattern involves luring users to click on these links, which are designed to appear legitimate but lead to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://papiratisk.cz/soubory/86501234201.pdf In PDF document text
    • http://lhdrum.com/User_File/UpFile/file/20210919015358_a293YW51a3VuYXh1bWluZWw=.pdfIn PDF document text
    • http://pho32shabu.com/uploads/files/besedaderi.pdfIn PDF document text
    • http://vit-physio.de/file/paxetebugewoxitigiziki.pdfIn PDF document text
    • https://inchiriereelicoptere.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613e94fd2a315---11044538867.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613aab1c73636---46520907290.pdfIn PDF document text
    • https://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/9987742d992d37ec895c3881b1c2deac/munomavumofi.pdfIn PDF document text
    • http://compagniaviaggi.gattinonimondodivacanze.it/themes/userfiles/files/nepubusu.pdfIn PDF document text
    • https://cafesca.org/ckfinder/userfiles/files/poxuberamidoper.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16130e891b275d---xetikapavunawig.pdfIn PDF document text
    • http://lotusromeo.fr/app/webroot/files/userfiles/files/tujofusirajag.pdfIn PDF document text
    • http://tumakuruvoice.com/tumkurvoice/ckeditor/ckfinder/userfiles/files/51328466408.pdfIn PDF document text
    • https://siroyensao.com/upload/files/61784340823.pdfIn PDF document text
    • https://viboot.traigiongthuha.com/ckfinder/userfiles/files/numovugagisikaderu.pdfIn PDF document text
    • http://www.xn----9sbkvfu2aex3d.xn--p1ai/ckfinder/userfiles/files/53900823600.pdfIn PDF document text
    • https://vpmemorial.net/images/file/12064085419.pdfIn PDF document text
    • http://salonorganica.ru/upload/files/gukapefekumejofogovu.pdfIn PDF document text
    • http://medicareclinichowrah.net/faboriginelist-braj/userfiles/file/76440165178.pdfIn PDF document text
    • http://poaglasses.com/uploads/files/202109140224127841.pdfIn PDF document text
    • http://bwlpsalisbury.com/uploads/files/94577601381.pdfIn PDF document text
    • https://sangolongphuong.vn/longphuong/news/files/45602558205.pdfIn PDF document text
    • https://universal4shipping.net/userfiles/file/juwuguwidune.pdfIn PDF document text
    • http://koreaseals.com/ckfinder/userfiles/files/17921209092.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=android+vs+apple+2020PDF 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_off0000b563.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB563 17776 bytes
SHA-256: 44b66f26dba13f0fdfcfab7a12fce8c087dd97d8ec1efe09666bb407716f06ef
font_01_sfnt_off0000e378.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE378 10576 bytes
SHA-256: 69dd70a9023418eac052127abbce366ed2509f1fae90b09ed4f885297bd9f5c3
font_02_sfnt_off0000fbc0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBC0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1