Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef6b6808af678ae1…

MALICIOUS

PDF

74.2 KB Created: 2021-09-14 23:42:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 713a767090a9a29d80ac544423c7c3b8 SHA-1: e30f216346223db5a26ec943611a50d850f9e8ec SHA-256: ef6b6808af678ae1693ed59173ab83524727cb3adb7e1d619c61dcdc94fc82a7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous links, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. While no scripts were explicitly extracted, the PDF structure and heuristic firings strongly suggest it's designed to exploit users via these external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://newsru.md/upload/userfiles/files/renudunuvodubi.pdf In PDF document text
    • https://fietenhaardenenkachels.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613d466ba6efd---keberibelininedefezefuve.pdfIn PDF document text
    • https://knurussian.kr/DATA/upload/files/202109061413557216.pdfIn PDF document text
    • http://tranindo.com/Uploads/userfiles/files/17641549011.pdfIn PDF document text
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139d593184b0---turonevixuzowanogixusesa.pdfIn PDF document text
    • https://nexusmediation.nl/files/vagixejawefezuxuzolo.pdfIn PDF document text
    • http://phelieuviethung.vn/upload/files/45321354218.pdfIn PDF document text
    • http://vivatbacchus.hu/files/file/39500894779.pdfIn PDF document text
    • https://derechosenred.org/aym_image/files/darebesuduru.pdfIn PDF document text
    • http://brenna-ski.pl/userfiles/file/60007840804.pdfIn PDF document text
    • http://bassonconsulting.mc/userfiles/file/ladavivuxefakedawer.pdfIn PDF document text
    • http://zrdb-drogbud.pl/Upload/file/46223177444.pdfIn PDF document text
    • https://securitydm.eu/slicice/file/dasirabufaroforobaw.pdfIn PDF document text
    • https://rainbowfurnitures.com/files/files/vakanedukex.pdfIn PDF document text
    • https://vdbergelectro.nl/wp-content/plugins/super-forms/uploads/php/files/fe54eca69541ee1ef13e079f2f6f8f3f/45652689348.pdfIn PDF document text
    • http://fratellilongoni.com/userfiles/files/topubo.pdfIn PDF document text
    • http://bptramptour.pl/files/file/90949501633.pdfIn PDF document text
    • http://herningbadintra.dk/app/webroot/upload/files/janone.pdfIn PDF document text
    • http://n3ss.ro/ckfinder/userfiles/files/zozosokox.pdfIn PDF document text
    • http://tl-maskinfabrik.dk/userfiles/file/24491421051.pdfIn PDF document text
    • https://art-eria.pl/mandarynka/pliki/files/62437690853.pdfIn PDF document text
    • http://kiko168.com/UploadFile/file/20210904092338774.pdfIn PDF document text
    • http://beloezoloto.ru/userfiles/file/bemijerod.pdfIn PDF document text
    • http://studioaba.net/userfiles/files/kifonubevagexo.pdfIn PDF document text
    • https://charterboatdeliverance.com/uploads/files/bimaz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=food+calories+list+in+tamil+pdfPDF link annotation
    • 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_off0000be92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE92 17116 bytes
SHA-256: e99ba2a0215eefdc72fa6041cb2a65e79e63431a5a02a123b75b0923482c6651
font_01_sfnt_off0000ea94.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA94 10756 bytes
SHA-256: 417093cfdbf916d4278065ce2d332e2dc873cfc9e33c190682b16796d699c71b
font_02_sfnt_off00010343.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10343 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1