Malicious PDF — malware analysis report

Static analysis result for SHA-256 91b1a0f32d4ee483…

MALICIOUS

PDF

89.0 KB Created: 2021-09-16 02:58:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: da1f83d683cb4a686df369baffc53d2d SHA-1: 818c2d6877947511794f144593b61ff49d4f7a6c SHA-256: 91b1a0f32d4ee48383e20b2ac492a9e54afd62725f4a1f5ff9f1915eb4a6fd2b
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to external domains, many of which are associated with link farms and disposable hosting, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of a malicious document designed to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://crewmak.ru/uplcv?utm_term=how+to+send+file+in+messenger+using+android+phone+2020 PDF link annotation
    • https://riminabda.sk/userfiles/file/nulunimugevopaju.pdfIn PDF document text
    • https://nada70.org/userfiles/file/jevid.pdfIn PDF document text
    • http://dedanskecasinoer.dk/userfiles/file/luvivupiguxoxurejajuri.pdfIn PDF document text
    • https://xosobacninh.vn/webroot/img/files/dajibemetumigako.pdfIn PDF document text
    • https://gaadalagi.com/contents/files/babofatekumobenukitik.pdfIn PDF document text
    • http://minhtoangalaxyhotel.vn/app/webroot/files/ckfinder/files/67798915679.pdfIn PDF document text
    • http://kosmonautika.ee/ckfinder/userfiles/files/25897646183.pdfIn PDF document text
    • http://gymostrov.org/gymostrov/userfiles/file/91557316424.pdfIn PDF document text
    • http://etkindenetim.com/resimler/files/3015993574.pdfIn PDF document text
    • https://fnb-concepts.com/images/uploads/files/71505610267.pdfIn PDF document text
    • http://smeeing.com/userfiles/files/14776809327.pdfIn PDF document text
    • http://tks-forever.com/upload/2021/09/15/file/fisava.pdfIn PDF document text
    • https://anandamsanyal.com/userfiles/file/54933644401.pdfIn PDF document text
    • http://studioarchperissinotto.eu/userfiles/files/lisaximafirizepawu.pdfIn PDF document text
    • http://uniquehotelsolutions.com/files/others/93630640449.pdfIn PDF document text
    • https://cafesca.info/ckfinder/userfiles/files/45030909057.pdfIn PDF document text
    • https://gionggiacam.com/ckfinder/userfiles/files/2742875951.pdfIn PDF document text
    • http://grani-tonkogo-mira.ru/wp-content/plugins/super-forms/uploads/php/files/7459a466a40ff7d023880f998d616679/69434686286.pdfIn PDF document text
    • http://sql110.com/pic/52564244106.pdfIn PDF document text
    • https://europartner2.pl/uploads/31253041741.pdfIn PDF document text
    • https://xn--80aesyq.xn--p1ai/files/file/negosokiw.pdfIn PDF document text
    • http://osoboebludo.com/ckfinder/userfiles/files/23512797625.pdfIn PDF document text
    • https://masterjobintl.com/ckfinder/userfiles/files/befotudenotijanejifura.pdfIn PDF document text
    • http://konikanarrowfab.com/ckfinder/userfiles/files/47914020772.pdfIn PDF document text
    • http://sugarfree-gelato.com/upload/file/zanirunal.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_off0000f335.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF335 11364 bytes
SHA-256: 85007b63eb51981ad0bb0acbfc63594d11cf98a3337a5b1c59f2c1b28033950a
font_01_sfnt_off00010d9d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D9D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000125af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125AF 18592 bytes
SHA-256: 6be88a1157b22389932e178f041963362fd4a7a9d52636d57d9758f4f96277e4