Malicious PDF — malware analysis report

Static analysis result for SHA-256 b499f72963de9cff…

MALICIOUS

PDF

101.3 KB Created: 2021-09-20 05:35:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 41a4957954f782ce342653826aac585c SHA-1: f73f8b4f2478f3c8e939658c12977eff78362460 SHA-256: b499f72963de9cffbd4ae64bb81895a32f025eceee2c76397a97c02e9866d037
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to other PDFs hosted on compromised websites or disposable domains, indicating a link farm designed to distribute malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware delivery. Although no scripts were explicitly extracted, the nature of the embedded URLs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic point towards a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9689

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://queure.ru/uplcv?utm_term=bloons+td+4+apk+download PDF link annotation
    • http://shangrilatheshow.com/ckfinder/userfiles/files/57027025101.pdfIn PDF document text
    • https://combrooncom.com/contents/files/wugojufukuwek.pdfIn PDF document text
    • http://chothuexeninhbinh.net/data/dulieu/files/nuzutopuzijoduzigubo.pdfIn PDF document text
    • http://awarelaxcentrum.cz/user_files/file/xojafaxogara.pdfIn PDF document text
    • https://sg-design.top/wp-content/plugins/super-forms/uploads/php/files/aecc06bbb2c227477c6889abb59a2961/48415377778.pdfIn PDF document text
    • https://ladulceseguros.ar/noticias/fckeditor/file/zugapefoxoliwefusajadoj.pdfIn PDF document text
    • https://fatheragneliti.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141d69c04cc8---dunofivonavirore.pdfIn PDF document text
    • http://apartmany.cucoriedka.sk/data/files/69487256887.pdfIn PDF document text
    • http://tokyoto.pl/UserFiles/file/13223820471.pdfIn PDF document text
    • https://noble-worldwide.com/wp-content/plugins/super-forms/uploads/php/files/5de4afeb46d7c235f68d039b96f58c39/mapuwedixeguvekari.pdfIn PDF document text
    • http://sm.ac.th/ckfinder/userfiles/files/46097073119.pdfIn PDF document text
    • http://shrlie.com/upload_fck/file/2021-9-20/20210920052933117697.pdfIn PDF document text
    • https://bahia-group.com/ckfinder/userfiles/files/jufelovedepele.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/lupivoba.pdfIn PDF document text
    • http://balony.dmuchance.eu/userfiles/file/limewesarokoti.pdfIn PDF document text
    • http://chiari-web.com/ckfinder/optimist/files/jebavifedukajedusitomux.pdfIn PDF document text
    • http://urgentcarepb.com/userfiles/file/43522984403.pdfIn PDF document text
    • http://cachnhietcacham.vn/Images_upload/files/4913834515.pdfIn PDF document text
    • https://manpowernepal.net/ckfinder/userfiles/files/32137223457.pdfIn PDF document text
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/ae127713b68f88f6b613cc687368cb4b/zomawofatesit.pdfIn PDF document text
    • http://phelieuviethung.vn/upload/files/sakobadujonaxo.pdfIn PDF document text
    • http://nuk-amro.de/userfiles/file/vodumeg.pdfIn PDF document text
    • https://bedandbreakfastholten.nl/userfiles/file/juzepagowabutikom.pdfIn PDF document text
    • http://bladensburg.abwingsmd.com/uploads/files/26527490036.pdfIn PDF document text
    • http://www.szphotar.com/admin/img/files/jimaku.pdfIn PDF document text
    • https://profesa.net/userFilesfile/fotexewuse.pdfIn PDF document text
    • http://nikkenj.com/userfiles/file/poruxiwegeji.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#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_off00012afb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12AFB 10372 bytes
SHA-256: 0899eadc2f41b6c818458dce02fdf15f1f0fce213e6f2e8d752028745e3469bf
font_01_sfnt_off000142b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x142B1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00015ac3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15AC3 19052 bytes
SHA-256: e7d3b59526cf4339edfda149521e0d1b81c57d5bd97da5ca8d1a4906ff0d961d