Malicious PDF — malware analysis report

Static analysis result for SHA-256 b6523fe7c0e684cc…

MALICIOUS

PDF

72.0 KB Created: 2021-10-01 03:12:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 7c2b1d2373d0ac7a90424f739188e30a SHA-1: ef65a5a5303556823dcc15987e208cf17faf6b38 SHA-256: b6523fe7c0e684cce0e78f741833891c72544a826a507180a4e19798e61e2b50
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection for 'Pdf.Phishing.Trojan' and an ML classifier indicating maliciousness. The presence of numerous external URIs, many of which are part of a link farm on disposable hosting, strongly suggests a phishing or malware distribution attempt. The document body is heavily obfuscated, preventing a clear understanding of its direct content, but the overall structure and heuristic firings point to a malicious intent to redirect users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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 https://huntic.ru/uplcv?utm_term=android+app+development+tutorial+in+tamil PDF link annotation
    • https://myparrotfood.com/user_files/files/92728484424.pdfIn PDF document text
    • http://dailyxedayhang.com/userfiles/files/jagepisinuzetulo.pdfIn PDF document text
    • http://anhbanglaw.com/userfiles/file/fotapusasix.pdfIn PDF document text
    • http://st03.it/userfiles/files/bivarupixuvuk.pdfIn PDF document text
    • http://www.kymenhome-etsinta.net/tiedostot/files/kagolimafizamovepow.pdfIn PDF document text
    • https://www.sesc.com.ua/wp-content/plugins/super-forms/uploads/php/files/5du7m2tu8r62kulvonp1u6ev73/23027381659.pdfIn PDF document text
    • http://gemaeldeundobjekte.de/uploads/files/rupitepisuxex.pdfIn PDF document text
    • https://studiecarriere.it/uploads/file/gugaxireveru.pdfIn PDF document text
    • http://cathugo-yachts.de/res/wysiwyg/file/90752070899.pdfIn PDF document text
    • http://marklaliberte.com/fckupload/file/zexurepawinelasabom.pdfIn PDF document text
    • http://centralgiving.com/media/userfiles/file/rikoraxezomefarutewata.pdfIn PDF document text
    • http://richardchong.com/userfiles/files/28522797402.pdfIn PDF document text
    • http://mueblesdepladur.es/1/userfiles/file/zudojororulixorevibebepar.pdfIn PDF document text
    • http://riverla.vn/uploads/userfiles/file/vusatipapikadanagudale.pdfIn PDF document text
    • http://zssadkowice.pl/pliki/taliv.pdfIn PDF document text
    • http://mayjack.com/upload/files/mumizevu.pdfIn PDF document text
    • https://marblobathware.ph/app/webroot/img/files/2429878092.pdfIn PDF document text
    • http://villalapinetafavignana.it/userfiles/files/44273053929.pdfIn PDF document text
    • http://generaltubi.com/container/ckfiles/files/pivubelededovefosiwavoj.pdfIn PDF document text
    • http://rafaelstore.ru/upload/files/wikisoxisusugugox.pdfIn PDF document text
    • http://yourtruck.be/upload/ckeditor/file/fuxigemekibomapute.pdfIn PDF document text
    • https://gaseg.com/wp-content/plugins/super-forms/uploads/php/files/d6g0isejo0rt8ko4ct60oke76d/fiwes.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_off0000b226.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB226 10532 bytes
SHA-256: d23e867108f421de6043be83ec05e81670bbe3cc97395ef10d14a4c2883852b3
font_01_sfnt_off0000ca17.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA17 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e229.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE229 18620 bytes
SHA-256: 6d592f8d4a7cc39a46b217e27a4c44e782d2f747cf8aea48b3bcb77f7c92d5a7