Malicious PDF — malware analysis report

Static analysis result for SHA-256 08f1dbe19f24c94c…

MALICIOUS

PDF

71.5 KB Created: 2021-09-27 16:36:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-07
MD5: f8285aaa35d93fbd5430859271373527 SHA-1: 5ee3af68c2e71373c267c647561eecce5bfe99b4 SHA-256: 08f1dbe19f24c94c817f9a265baffdebe6d6057174592971edd1c4a668909508
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs pointing to various PDF files hosted on different domains, suggesting a link farm or SEO manipulation tactic. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly supports this, indicating the PDF's purpose is to redirect users to a network of disposable hosting sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9837

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://alves.bg/ckfinder/userfiles/files/peduvujelarabeziwe.pdf In PDF document text
    • https://fetogram.com/images/upload/files/70951788732.pdfIn PDF document text
    • http://mlead.net/images/e/file/dejugara.pdfIn PDF document text
    • http://yameitecl.com/ckfinder/userfiles/files/20210916_003032.pdfIn PDF document text
    • https://rivieresoceanie.com/userfiles/file/95756979022.pdfIn PDF document text
    • http://hb-hospital.com/file_upload/fck_upfile/file/17868709819.pdfIn PDF document text
    • https://centrehistoriquesndbc.com/ckfinder/userfiles/files/36681369075.pdfIn PDF document text
    • http://studiorinaldibedin.eu/userfiles/files/39329388572.pdfIn PDF document text
    • https://triatlonshop.cz/userfiles/file/kilusalarijadesi.pdfIn PDF document text
    • https://www.auto-ecole-rive-droite.fr/ckfinder/userfiles/files/44344585306.pdfIn PDF document text
    • http://qualityfirstservices.pro/testingsites/advantage_aviation/assets/media/file/27659586089.pdfIn PDF document text
    • http://pomocnaukowa.net/Upload/file/25846014812.pdfIn PDF document text
    • http://biemmecommerciale.eu/userfiles/files/71501140419.pdfIn PDF document text
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/16130eec569667---59337342454.pdfIn PDF document text
    • http://medicom.pl/userfiles/file/85420991998.pdfIn PDF document text
    • http://jadever.vn/Images_upload/files/xomavopewuko.pdfIn PDF document text
    • https://episcopiaoradiei.ro/files/jefuwalarozojajulisob.pdfIn PDF document text
    • http://balalajka.nu/media/28366468000.pdfIn PDF document text
    • http://tiwtactic.com/userfiles/files/tatosibenidef.pdfIn PDF document text
    • http://nikkenj.com/userfiles/file/zekagadabamajiwoxobuzisu.pdfIn PDF document text
    • http://jlsxjy.com/right/UploadFile/file///2021090600391073499.pdfIn PDF document text
    • https://nazrabilisim.com/calisma2/files/uploads/40651528360.pdfIn PDF document text
    • http://yamamatoen-wanwan.jp/ckfinder/userfiles/files/bezajakuwegepunuv.pdfIn PDF document text
    • https://postelezmasivu-ostrava.cz/ckfinder/userfiles/files/56289729329.pdfIn PDF document text
    • http://signexpowholesale.com/project-new/christianbook/upload_images/file/wurifunujojoweromak.pdfIn PDF document text
    • https://holycrosshealthcare.com/userfiles/files/81374011702.pdfIn PDF document text
    • http://netinflux.net/userfiles/file/buresiwaguveb.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=why+mms+not+working+on+androidPDF 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_off0000b485.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB485 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cc97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC97 16928 bytes
SHA-256: 91c6d85c5e41c03503aeb978c3b63ba0e20c65458dd5b04f84807c26618685eb
font_02_sfnt_off0000f7db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7DB 10800 bytes
SHA-256: f3d4a89e22d159f683d7d999a28b20986b3ef8ab10b75da50804a4c38b90b844