Malicious PDF — malware analysis report

Static analysis result for SHA-256 388603652bddbaaf…

MALICIOUS

PDF

74.7 KB Created: 2021-09-03 11:16:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: b77dcac9cdd7cdfdd9c56851d7bc6e0a SHA-1: f8c9241fdea40ce3f2475a19646afd9a31018897 SHA-256: 388603652bddbaaf6be15f9b8768fc1244d7b219ff9e535602b7900adea6005d
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to distribute malicious content. ClamAV detection and ML classification confirm its malicious nature, likely as a phishing or malware distribution lure. The file's structure and numerous external links indicate an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://k-barrierfree.com/FileData/ckfinder/files/20210722_6CF251B09B0C6D22.pdf In PDF document text
    • http://viswinkelindex.nl/images/uploads/vuxogumowebazagusibidi.pdfIn PDF document text
    • http://www.premiumimport.nl/ckfinder/userfiles/files/57486924200.pdfIn PDF document text
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c746f095db4---solumuzifufewajenezuxike.pdfIn PDF document text
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607144b08615c---lilodedinufok.pdfIn PDF document text
    • https://big-cash.de/wp-content/plugins/super-forms/uploads/php/files/qlpuehks47t5pslvqus1b06rtj/widelupesixogowo.pdfIn PDF document text
    • https://cairparavel.ro/app/webroot/files/userfiles/files/kafolid.pdfIn PDF document text
    • https://www.abaco-engineering.it/wp-content/plugins/formcraft/file-upload/server/content/files/160ae8242a2017---figemeko.pdfIn PDF document text
    • http://chhattisgarhsanskritboard.in/sharpinstitute/images/files/zekirewakelokuj.pdfIn PDF document text
    • http://www.hj-bouwt.be/wp-content/plugins/formcraft/file-upload/server/content/files/160df4d6793ca9---baxurijonojobugenez.pdfIn PDF document text
    • http://language-coach.pl/uploads/files/92590568209.pdfIn PDF document text
    • http://matstravel.ru/userfiles/file/73366536743.pdfIn PDF document text
    • https://lasanisports.com/files/58289410134.pdfIn PDF document text
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/7ums3esk4q460bicmol268a1bs/62704253430.pdfIn PDF document text
    • http://760_709737661.mildmedia-dev.eu/uploads/userfiles/files/97901142002.pdfIn PDF document text
    • http://club-integra.ru/userfiles/file/romavevu.pdfIn PDF document text
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/160a3b7dc6e15d---41184507163.pdfIn PDF document text
    • https://independentmusicleague.com/wp-content/plugins/super-forms/uploads/php/files/29ac5dcf36ca01a7a763866c0611927a/gegademawodozuga.pdfIn PDF document text
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d27e6696090---wakifimolekiz.pdfIn PDF document text
    • http://szyoujin.com/UploadFile/file/20210730034459551.pdfIn PDF document text
    • http://dienlanhtruongson.com/upload/files/tefofil.pdfIn PDF document text
    • http://rasmesafar.net/basefile/basefiles/85964529547.pdfIn PDF document text
    • https://sdyh.gr/wp-content/plugins/super-forms/uploads/php/files/dbn9bs11cr0j9m5nal3j454cl2/80713279942.pdfIn PDF document text
    • https://tectrongim.com/uploads/files/lubufudubilapeporot.pdfIn PDF document text
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/161057f1b6d0a9---77348666597.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=comptia+network%2B+study+guide+pdf+freePDF 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_off0000c0e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC0E5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d8fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8FC 11220 bytes
SHA-256: 26520d8da59767f6df2e8140e09d3507d51b5c8c175f27b47741ec078c4abb77
font_02_sfnt_off0000f328.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF328 16192 bytes
SHA-256: 904de50ab0fd501d7bee996b7cd87d4e1d1ccb4d206e9e69c5d6bdd652f95148