Malicious PDF — malware analysis report

Static analysis result for SHA-256 35ff373c1eff40fe…

MALICIOUS

PDF

73.3 KB Created: 2021-10-09 05:17:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: b4416815be396f9afab936bf1217c2cd SHA-1: dadba6683cda1d009ca77160cb608c54eb84289c SHA-256: 35ff373c1eff40fe25b1e3c4890e51f0fccef8d804cdcc1677484adb6cee337b
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS uploads, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are typical of a malicious PDF used as a lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 http://cerritos.songhakbbq.com/uploads/files/goroxukanawuto.pdf In PDF document text
    • http://boldogelet.hu/media/32940885082.pdfIn PDF document text
    • http://zangerlelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/xozux.pdfIn PDF document text
    • https://soccerauquebec.com/userfiles/file/zezuf.pdfIn PDF document text
    • http://www.ssc-ras.ru/ckfinder/userfiles/files/xuzonerusedule.pdfIn PDF document text
    • https://inprovitbolivia.com/ckfinder/userfiles/files/89061168894.pdfIn PDF document text
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132a1cb6053b---dewowuzapiwanubo.pdfIn PDF document text
    • http://weddingdove.tw/uploads/files/202109282354097813.pdfIn PDF document text
    • http://naturalmis.com/userfiles/file/melabifoxak.pdfIn PDF document text
    • http://oumkua.com/userfiles/file/sedusivorikugedugifiwewuv.pdfIn PDF document text
    • http://coomargroup.com/ckfinder/userfiles/files/zusowitemoliposojez.pdfIn PDF document text
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/b4f4dcb685fd304740ab374db4dcd7af/97427332198.pdfIn PDF document text
    • https://formapolis.it/wp-content/plugins/super-forms/uploads/php/files/5f9669e5c886501f21678990368fd18b/17187127560.pdfIn PDF document text
    • http://tinhdauvietnam.vn/upload/files/bodog.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/161421ded5ff7e---34987629308.pdfIn PDF document text
    • https://dcicz.org/userfiles/file/78455511905.pdfIn PDF document text
    • https://khonggiansangtao.com/platformecom/img/upload/file/wugezexevukesil.pdfIn PDF document text
    • http://greenworx.eu/images/uploads/files/tileve.pdfIn PDF document text
    • http://daindnc.com/fckeditor/userfiles/file/rebapajilamobizuba.pdfIn PDF document text
    • https://sowlindia.com/userfiles/file/14364528397.pdfIn PDF document text
    • https://mytalk7.com/_UploadFile/Images/file/82216262492.pdfIn PDF document text
    • https://www.ftha.org/admin/ckfinder/userfiles/files/pigotul.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=burned+out+or+burned+outPDF 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_off0000c01c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC01C 10064 bytes
SHA-256: 51d52b011aded82d9c58521cd55aad686d54ec167c13dae9f8d2484e7b7b1a8a
font_01_sfnt_off0000d69d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD69D 16168 bytes
SHA-256: 7e791b6f0b55f9fe6a573602ce85e3055a783e261c80df9a93c2395d398ef671
font_02_sfnt_off0000ffc1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFC1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1