Malicious PDF — malware analysis report

Static analysis result for SHA-256 b843a474883bf3af…

MALICIOUS

PDF

93.8 KB Created: 2021-08-13 09:33:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: a0f16cc07d98106e011a1465b21cf557 SHA-1: 2c48f984a789a13c9d2647b10b267d2d842b6517 SHA-256: b843a474883bf3afa70e8bea2970c64891da0215fe9623db7e90654b617e38ae
156 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, with multiple heuristics indicating it functions as a link farm. The embedded URLs and PDF structure suggest an attempt to direct users to compromised websites, likely for phishing or further malware delivery. The document body is heavily obfuscated and does not provide clear textual content, but the overall pattern points to malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://medvor.ru/uplcv?utm_term=giorno%27s+theme+virtual+piano+sheet+easy PDF link annotation
    • http://goldnumber.info/userfiles/file/96375390807.pdfIn PDF document text
    • http://amuseonline.com/absite/userfiles/file/xexamaxurukaroberinidum.pdfIn PDF document text
    • https://universitecentrale.net/uploads/FCK_files/file/jazadusapitojir.pdfIn PDF document text
    • http://nccutrackandfieldnation.com/clients/2/2c/2cea5a7e730406ee40dfbbde6098010c/File/bururasereki.pdfIn PDF document text
    • http://giadinhmedia.com/uploads/files/zobibujare.pdfIn PDF document text
    • https://arnetbilgisayar.com/upload/ckfinder/files/49428303831.pdfIn PDF document text
    • https://candica.pl/ckfinder/userfiles/files/96891799374.pdfIn PDF document text
    • http://czerwoneiczarne.pl/files/file/naxoruje.pdfIn PDF document text
    • https://www.agencesramos.com/ckfinder/userfiles/files/jufavevumesamejofelizet.pdfIn PDF document text
    • https://bowenpainter.com/wp-content/plugins/formcraft/file-upload/server/content/files/160af8c354ec5c---23240834346.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/160ad93150287b---wavetinubaxexosepenozu.pdfIn PDF document text
    • http://bethtikvahevents.ca/clients/2/20/20a91c0cb94b02964b0d1c5d980f1596/File/39086484385.pdfIn PDF document text
    • https://southtours.com/wp-content/plugins/super-forms/uploads/php/files/jji1ovl1l6sq2a732i6qrhohsu/tizetiditexukepedi.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fd11a68c32---morazoxaxalotitonezejexa.pdfIn PDF document text
    • https://studiopros.com/userfiles/file/In PDF document text
    • https://xn--80afc2apd5n.xn--j1amh/upload/files/dadamosebagikukax.pdfIn PDF document text
    • https://www.abaco-engineering.it/wp-content/plugins/formcraft/file-upload/server/content/files/160f4628924a95---vimekukujekexopukujuduwox.pdfIn PDF document text
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607318f7584c0---31227903455.pdfIn PDF document text
    • https://actorconseil.com/files/file/juxasakenuxijuzu.pdfIn PDF document text
    • http://www.como-grup.ro/fisiere/file/xotebeto.pdfIn PDF document text
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/kvra3mt7icffnesr9ja45iqosu/46528863759.pdfIn PDF document text
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/16081af8100210---20178547046.pdfIn PDF document text
    • http://diagonal.org.ar/wp-content/plugins/formcraft/file-upload/server/content/files/16074b4e8535f1---4338815486.pdfIn PDF document text
    • https://christembassybarking.org/wp-content/plugins/super-forms/uploads/php/files/803a1a220bffd60ea7c189030632ce67/28935304830.pdfIn PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160c6212ec4bd0---xirujivakix.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/52226199085.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_off0000fcad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCAD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000114bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114BF 22940 bytes
SHA-256: 475882f7842519e0fb16ab81776b3a590b39be9eea3b70add98700d06d947d12
font_02_sfnt_off00015098.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15098 10868 bytes
SHA-256: 3886fa7a9705e09c97ff9a25a78a97133318e78462494e2af2ddd8dbd9a33d02