Malicious PDF — malware analysis report

Static analysis result for SHA-256 71f21ef95c1590df…

MALICIOUS

PDF

69.2 KB Created: 2021-09-24 15:58:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 378d5d3ec2b284ba9f90bf8b3d5f691d SHA-1: 1a1c4b9eb8d345ed7972aaa7fc1db814697cc1d0 SHA-256: 71f21ef95c1590dff1a2edd0abc411bfd0eb8fd143ab1ae2c2fb894a5d48946c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious document delivery mechanisms.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

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://ketchas.ru/uplcv?utm_term=cloud+based+server+backup+services PDF link annotation
    • https://szalkasszorutacskok.hu/app/webroot/files/content/files/pezurosedivoxuko.pdfIn PDF document text
    • http://skonasystems.com/userfiles/file/mitoretarewawo.pdfIn PDF document text
    • http://softwarefactory.nl/images/file/jifetu.pdfIn PDF document text
    • https://doxity.ro/ckfinder/userfiles/files/57216529194.pdfIn PDF document text
    • http://urduhadith.org/survey/userfiles/files/wunewoda.pdfIn PDF document text
    • http://ipayon.com/root/FCKeditor/file/sasuraderaloxagasolodexel.pdfIn PDF document text
    • https://whiteplacard.com/UserFiles/file/30791766861.pdfIn PDF document text
    • https://topinsolventa.ro/userfiles/file/tugixizewajel.pdfIn PDF document text
    • http://floramarble.com/uploads/1224055043.pdfIn PDF document text
    • http://stefanourso.com/public/userfiles/file/dipurisipelobifirumos.pdfIn PDF document text
    • http://djapm.com/userfiles/file/vogumaz.pdfIn PDF document text
    • http://ryouhurt.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/86896546770.pdfIn PDF document text
    • http://studiogiamberardino.it/userfiles/files/51902284129.pdfIn PDF document text
    • https://netshopnepal.com/userfiles/file/22461565170.pdfIn PDF document text
    • http://zonwering-belgie.eu/ckfinder/userfiles/files/zerog.pdfIn PDF document text
    • https://topconta.ro/userfiles/file/38448241325.pdfIn PDF document text
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bd7937050f---43001865168.pdfIn PDF document text
    • http://architettosbaffo.com/userfiles/files/63202831539.pdfIn PDF document text
    • http://aaz.sk/editor_uploads/files/suwisasesejix.pdfIn PDF document text
    • https://www.lavishlook.se/wp-content/plugins/super-forms/uploads/php/files/4625a195e2f154aa151dddffc2f1d249/80769482845.pdfIn PDF document text
    • https://drhuanghair.com/uploads/files/202109150611386698.pdfIn PDF document text
    • http://paulgraphics.paulsfashion.in/files/wafirovifo.pdfIn PDF document text
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/pdcnibk0d1mrrclv24ru8rld90/livuben.pdfIn PDF document text
    • http://tiquital.com/documentos/file/tagejavujebenodarasuku.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_off0000aff3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAFF3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c805.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC805 14676 bytes
SHA-256: 79e5df2f0c5a4059b312168219d634e776b024548c9f20c90479938f82740499
font_02_sfnt_off0000ecf5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECF5 10732 bytes
SHA-256: b16c2991c8ee7707767fb776c7f715266abc58cbcceb79be49d5230e5312febf