Malicious PDF — malware analysis report

Static analysis result for SHA-256 6bd4b38acdef71f0…

MALICIOUS

PDF

68.4 KB Created: 2021-09-27 16:29:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 575fef1f4cc9aa43b6d50e0b91356f32 SHA-1: ac9d6b5aa69f8f2b832b9c71f4ad481974d54e84 SHA-256: 6bd4b38acdef71f0e0274455fc5d2112dd1992581a98735416b42cb5379f69ae
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. While no scripts were explicitly extracted, the nature of the URL farm and the high detection scores point to a malicious document, potentially leveraging embedded JavaScript for redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 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://drafthe.ru/uplcv?utm_term=modal+nouns+examples PDF link annotation
    • http://crystal-lamp.ru/uploads/files/xiwerupevolofigator.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/7946c14b5064e6e696edcc5dc47a6810/wopowuximopoma.pdfIn PDF document text
    • https://www.ijdsir.com/ckfinder/userfiles/files/surazisokibe.pdfIn PDF document text
    • http://andreaslasnik.com/data/files/63912158849.pdfIn PDF document text
    • http://www.loicadesacavem.pt/wp-content/plugins/formcraft/file-upload/server/content/files/161496659be5b7---70811242250.pdfIn PDF document text
    • http://michaelwilliamslaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/77476773332.pdfIn PDF document text
    • https://mkting.com.co/wp-content/plugins/super-forms/uploads/php/files/b87762d82e75b15d7bc7f1452defd575/62482109585.pdfIn PDF document text
    • http://aydinservis.com/ckfinder/userfiles/files/59760430727.pdfIn PDF document text
    • http://scea.edu.mn/ckfinder/userfiles/files/mezipiguranepe.pdfIn PDF document text
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614e729db33d6---nisafutimi.pdfIn PDF document text
    • https://lifeteacher.tw/uploads/files/202109250438511769.pdfIn PDF document text
    • http://yevres.fr/ckfinder/userfiles/files/zenapofami.pdfIn PDF document text
    • http://birkhoffhi.com/userfiles/files/kosowikosokuwogubebime.pdfIn PDF document text
    • http://nanobubblevietnam.com/uploads/userfiles/file/gagawutokilewufadij.pdfIn PDF document text
    • https://speedwayinfo.hu/uploads/file/41295319400.pdfIn PDF document text
    • http://www.mondzorgvesa-voorschoten.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613d02acbf64f---neziguxukavazajemananisap.pdfIn PDF document text
    • http://6nergy.fr/6nergy/sites/default/user/file/66220790899.pdfIn PDF document text
    • http://ngocvietbungalow.com/upload/files/mowanobelaji.pdfIn PDF document text
    • http://kirakuramen.com/uploads/files/tusunamalogodanijaboj.pdfIn PDF document text
    • https://jasmijnbloemengroen.nl/userfiles/file/siwakiwowuxuvo.pdfIn PDF document text
    • http://altronic.pl/!mag2011/userfiles/file/72102662915.pdfIn PDF document text
    • https://indiantalentjunction.com/milan/media/65783606388.pdfIn PDF document text
    • https://topupdana.com/contents/files/gopapenegejupowagigetux.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146f77908bb8---61043792455.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_off0000b04a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB04A 14556 bytes
SHA-256: 2c591ac31a505a21bcd52497cbe9bd3482ad24b100e08089bb79f36f9fc0dd5a
font_01_sfnt_off0000d4b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4B1 10460 bytes
SHA-256: ca2526ed2817da9df0a6ba0416d636ab9ae19359e164365e8e73d5b69280d75d
font_02_sfnt_off0000ec6c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC6C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1