Malicious PDF — malware analysis report

Static analysis result for SHA-256 df06538bd5158e81…

MALICIOUS

PDF

70.3 KB Created: 2021-09-19 09:51:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 5b43d5a4acba26320ce5435d3b30ef6b SHA-1: 88f95daa819d5de80ca862f4048b0a5d79e1770f SHA-256: df06538bd5158e813aece57e3d2cc6e7e7294d9758f76c7429050fd0c1fdced8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. The presence of multiple PDF-specific heuristics related to URI and link farms reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://catamma.ru/uplcv?utm_term=wifi+hack+no+root+apk PDF link annotation
    • https://brune-schmuckwerk.de/ckfinder/userfiles/files/ruxuravugirewuvirobasam.pdfIn PDF document text
    • http://flomojapan.com/upload/files/dujerotutafatobazo.pdfIn PDF document text
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136508b10783---lurupixoz.pdfIn PDF document text
    • http://vizit-k.net/uploads/editor/files/xemudanawad.pdfIn PDF document text
    • http://fw-simple.com/uploads/files/91765112164.pdfIn PDF document text
    • http://planao.com/ckfinder/userfiles/files/zuzenenilo.pdfIn PDF document text
    • https://mjrspot.com/fckimages/file/wagafinakafiza.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/96b15b6686434265fa15fa7dc13e9782/boderutigipisajulovexixeg.pdfIn PDF document text
    • http://chono.mn/uploads/userfiles/files/66510895324.pdfIn PDF document text
    • http://clinivetmadonnadirosa.eu/userfiles/files/35172850921.pdfIn PDF document text
    • https://toliveinchristjesus.ceosale.catholic.edu.au/application/third_party/ckfinder/userfiles/files/95895667152.pdfIn PDF document text
    • http://thesecurityguardunion.ca/userfiles/files/56810452500.pdfIn PDF document text
    • http://www.kickcommerce.com/userfiles/file/84082637516.pdfIn PDF document text
    • http://msslink.ru/userfiles/files/pigosevuzan.pdfIn PDF document text
    • http://midel.me/userfiles/file/ramogajosowixik.pdfIn PDF document text
    • http://zlhk.ru/upload_picture/file/zokuzevonovujitene.pdfIn PDF document text
    • https://www.paparazzirestaurant.com.au/wp-content/plugins/super-forms/uploads/php/files/146f9a3d91c73009a69643612e2b7729/rupijiwo.pdfIn PDF document text
    • http://aias.pnu.ac.th/ckfinder/userfiles/files/21213061854.pdfIn PDF document text
    • https://travelselection.us/wp-content/plugins/formcraft/file-upload/server/content/files/161367c120b998---22826876025.pdfIn PDF document text
    • http://ylpqzl.com/ckfinder/userfiles/files/66866525084.pdfIn PDF document text
    • http://studiosantomauro.it/userfiles/files/51182664614.pdfIn PDF document text
    • http://shinserviceodi.ru/wp-content/plugins/super-forms/uploads/php/files/88174cc4cdfc26447d800584d0812a1f/65020439040.pdfIn PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/161416d44125fb---ratolenejipigivuderejubum.pdfIn PDF document text
    • https://pjkconstruction.ca/images/file/loviwazeba.pdfIn PDF document text
    • http://www.europesolidaire.eu/userfiles/files/perulokatarenunebege.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_off0000b651.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB651 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ce68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE68 10316 bytes
SHA-256: 7b68d61714a51183cdb8fd83bbdf473bf0c58e7d168e84e929244f604491be6f
font_02_sfnt_off0000e5a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5A3 14948 bytes
SHA-256: cf5841f828a3253da984b2757e400f6b5c044ce1d35636a92ceb8e78ec184b43