Malicious PDF — malware analysis report

Static analysis result for SHA-256 7ddb8f4c2532b1c0…

MALICIOUS

PDF

81.0 KB Created: 2021-09-17 11:52:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 03f8db4418f44ab3f9f7d87dc14eac1b SHA-1: 68cba18a9b5bc1e9d34b398dc6897a35a872d811 SHA-256: 7ddb8f4c2532b1c07939177c70f601fac6f27844b256fab54ca85c3752a4320e
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. The PDF contains numerous external URIs pointing to various domains, many of which are structured to appear as file downloads, suggesting a link farm designed to redirect users to potentially malicious content. An embedded JavaScript stream was also detected, which could be used to further obfuscate the malicious intent or facilitate exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://archism.ru/uplcv?utm_term=naming+a+blog PDF link annotation
    • http://sentezetutmerkezi.com/upload/ckfinder/files/77155536662.pdfIn PDF document text
    • http://jawarakreasi.com/file/lowid.pdfIn PDF document text
    • http://elcolono.net/userfiles/files/popudorusuwisuregafo.pdfIn PDF document text
    • https://egokituz.eus/files/galeria/files/96363884286.pdfIn PDF document text
    • https://www.wizzfizz.com.au/application/third_party/ckfinder/userfiles/files/wepinegeketinoz.pdfIn PDF document text
    • http://vititanon.com/user_img/files/74444285372.pdfIn PDF document text
    • https://fortlauderdale-carservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ea2ac459b7---mowirolipevap.pdfIn PDF document text
    • http://futurepoolandspa.com/ckfinder/userfiles/files/65222766223.pdfIn PDF document text
    • https://blsautomation.com/ckfinder/userfiles/files/botomija.pdfIn PDF document text
    • https://atputasbaze.lv/images/userfiles/files/guremum.pdfIn PDF document text
    • http://nexxstep.nl/userfiles/file/61752608137.pdfIn PDF document text
    • http://divorcefinance.nl/uploads/file/10259039038.pdfIn PDF document text
    • http://perechen-jurnalov.ru/js/ckfinder/userfiles/files/65821211234.pdfIn PDF document text
    • https://www.truckersplantparts.co.uk/ckfinder/userfiles/files/gufuzile.pdfIn PDF document text
    • https://wisestudentz.com/userfiles/file/36397003944.pdfIn PDF document text
    • https://art-gallery.mn/uploads/files/ximukakudexadoxutom.pdfIn PDF document text
    • https://efckrakow.pl/userfiles/file/30124493253.pdfIn PDF document text
    • http://orthopediedelft.eu/files/24634342574.pdfIn PDF document text
    • http://biaikatolikus.hu/files/file/33289156692.pdfIn PDF document text
    • https://agriturismoilcolle.org/userfiles/file/mezutowe.pdfIn PDF document text
    • http://alfatreyd-mebel.ru/archive/images/file/jiramalef.pdfIn PDF document text
    • https://ddtoyz.com/ckfinder/userfiles/files/23096635508.pdfIn PDF document text
    • https://phase1acoustics.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141522686455---16970993787.pdfIn PDF document text
    • https://cakamuzejs.riga.lv/ckfinder/userfiles/files/pufukidunokevo.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_off0000dc1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC1F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f431.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF431 16912 bytes
SHA-256: 79573c2a98f46423fe48d9149552b7a5d931c6af2bd7ba19f62d463305cd8f76
font_02_sfnt_off0001204b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1204B 10068 bytes
SHA-256: de468da69c472ef1e3d6569d881d2e0cedb376058c42cf9f753c244125f79411