Malicious PDF — malware analysis report

Static analysis result for SHA-256 1dafcd1c508a74c1…

MALICIOUS

PDF

87.7 KB Created: 2021-08-23 12:59:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 23d6abd22e17bddcbbcd6289f9f3fd44 SHA-1: 939028619cc7db1925bafed282195074e4274441 SHA-256: 1dafcd1c508a74c14c50161f2a52f1fe263ebff0baa4e67fae632b6e80bdb88b
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It functions as a link farm, containing numerous URLs pointing to compromised CMS uploads and disposable hosting, likely intended to lure users to malicious content. The document body is heavily obfuscated and appears to be non-readable content generated by wkhtmltopdf.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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 http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611aeb28aab49---14775468158.pdf
    • http://medicaldistri.com/ckfinder_files/files/65522292386.pdf
    • https://vandolderskb.com/images/usr/92652721421.pdf
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16096680d2df03---18600096729.pdf
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160c1e0129c642---72647846286.pdf
    • https://www.digitalsofts.com/wp-content/plugins/formcraft/file-upload/server/content/files/160acfeadf1a35---29097469600.pdf
    • http://brodart01.com/wp-content/plugins/super-forms/uploads/php/files/s0mucdmmqv8b6ra37rkobhdv0l/lujadabixowo.pdf
    • http://meuble-tunisie.com/userfiles/file/gafolotonotazobogurafimo.pdf
    • http://www.blueoak.fr/image/file/21527678449.pdf
    • http://meruzhankhachatryan.com/app/webroot/files/file/63987227525.pdf
    • http://jejuecotech.com/ckupload/files/gutelasinajikozo.pdf
    • http://puppiesulove.com/clients/7/7f/7fa6d7836ea929643a3c23f4562b158d/File/68308792303.pdf
    • http://h-n-s.net/userfiles/file/nakatajezupado.pdf
    • http://sewakendragroup.com/userfiles/file/83435643058.pdf
    • https://stillwaiting.org/userfiles/file/butezajotime.pdf
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c295e6010c4---26496466926.pdf
    • http://cadeco.com/testingsites/advantage_aviation/assets/media/file/51335301570.pdf
    • https://martybermanassociates.com/wp-content/plugins/super-forms/uploads/php/files/45a65ebd55636c6487df5e38ff7ca943/85411244752.pdf
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610b6cc2c090c---85954656006.pdf
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d81f22caaa5---61957973943.pdf
    • http://xn--90aoa5aj.xn--p1ai/ckfinder/userfiles/files/47644772951.pdf
    • http://zaun-produzent.de/userfiles/file/bifixiwelisaxapabam.pdf
    • http://korea-seals.com/ckfinder/userfiles/files/73528202012.pdf
    • https://paklya.su/design/img/upload/file/josadetexe.pdf
    • https://chocoinmobiliario.com/wp-content/plugins/super-forms/uploads/php/files/16210b57c7c722e2e59c3e778fb811b1/34982413538.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=picture+answer+app
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f336.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF336 16792 bytes
font_01_sfnt_off00010b4d.bin
2ac691f85dbce44e57a18ac751276d2edc6c020fecedf6b97f12a05c0bfd9846
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B4D 10388 bytes
font_02_sfnt_off00012305.bin
614474433364c606521b991bb712e22a8f09a68d4ef4cdc0eecd11b9c1ea185d
pdf-font-stream PDF embedded font (sfnt) at offset 0x12305 17228 bytes