Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1243fd7116b6eed…

MALICIOUS

PDF

70.6 KB Created: 2021-09-24 19:01:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 57eb3dd00025127ad65f716583a51e22 SHA-1: c27a3a5f5baaae627d0bbec8b783778033b175eb SHA-256: b1243fd7116b6eed5705e03b6dc96e0213beba739f09732fb25542dcaf3e8606
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to disposable domains and presented as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. While no scripts were directly extracted, the PDF structure and URL patterns are consistent with techniques used to deliver second-stage payloads or redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://drafthe.ru/uplcv?utm_term=iphone+mp3+downloader PDF link annotation
    • http://problemconsulting.com/img/download/files/pegujajijiz.pdfIn PDF document text
    • http://studiomedicoveterinariobellucci.eu/userfiles/files/5845971849.pdfIn PDF document text
    • http://fluorescent-training.com/file/63827007468.pdfIn PDF document text
    • http://aokunoil.com/ckfinder/userfiles/files/wipaxolasixisirozawa.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613ec6c049148---faropusepotilinewoduw.pdfIn PDF document text
    • https://inprovitpuertorico.com/ckfinder/userfiles/files/jebekipevobufemoluzaz.pdfIn PDF document text
    • https://tselectromechanical.com/uploads/CKfiles/files/23166011146.pdfIn PDF document text
    • http://zoncmswebsitebeheer.nl/files/editor/file/jebiseruzofeme.pdfIn PDF document text
    • https://evenements.gipso.org/ckfinder/userfiles/files/logigotiwepedububog.pdfIn PDF document text
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613d520875f06---27692516802.pdfIn PDF document text
    • http://tiszaladany.hu/upload/file/poguwavosususox.pdfIn PDF document text
    • https://syteq-pro.com/userfiles/file/muzinuvil.pdfIn PDF document text
    • https://croatia-flyfishing.com/files/pisepojujuxujenarolep.pdfIn PDF document text
    • http://ks-system.co.uk/ckfinder/userfiles/files/dulaberanaxubeji.pdfIn PDF document text
    • http://e-motyle.natura2000.pl/imgturysta/files/wufuduzagawotebifat.pdfIn PDF document text
    • https://akvaguru.hu/user/file/xevamafutetetozedodopame.pdfIn PDF document text
    • http://scouttautomotive.com/editor_uploads/system/files/lesuvebob.pdfIn PDF document text
    • http://csc025.com/userfiles/file/20210915203840_k8xtde.pdfIn PDF document text
    • http://smolninskayahotel.com/userfiles/file/wanam.pdfIn PDF document text
    • http://aurangabadptti.com/ckeditor/ckfinder/userfiles/files/55667016096.pdfIn PDF document text
    • http://kartinatv.org/uploads/files/93588020507.pdfIn PDF document text
    • https://aodaixuan.vn/app/webroot/upload/image/files/mawupiriruzafur.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_off0000b1c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1C2 16788 bytes
SHA-256: 272f9dbd6e4573c71358866ee07ebb98eb33fa7a459accb801e552b3f531edbd
font_01_sfnt_off0000dcf8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCF8 10508 bytes
SHA-256: 35ac5cf41de7f40a2307f0011737fb88a3398d2993d50995598673f3292da0ed
font_02_sfnt_off0000f4b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4B3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1