Malicious PDF — malware analysis report

Static analysis result for SHA-256 4dc6b638580dac6f…

MALICIOUS

PDF

71.8 KB Created: 2021-09-04 15:20:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ca5bcf33c44e7710e09c9a58d641ac74 SHA-1: d34ae6ab4a7cf1ac676118335fbfbc33131a34d7 SHA-256: 4dc6b638580dac6f5f335cae70e288e9b125b674bee7ebe75e492602bca434e5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The numerous embedded URLs, many pointing to compromised CMS upload directories or disposable hosting, suggest a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and unreadable, but the presence of external URIs and the overall heuristic profile indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://huntic.ru/uplcv?utm_term=modern+labor+economics+ehrenberg+pdf
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/ksgqp1fejjikkcktct1oria62h/18788508346.pdf
    • http://toyotarenta.net/FileData/ckfinder/files/20210803_DF30C910BA467D33.pdf
    • https://cecprint.com/images/file/vurujodon.pdf
    • http://volamtuyetthe.com/userfiles/file/59664825760.pdf
    • https://www.couleurs-et-jardin.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160e4ecf809b40---72360759998.pdf
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/a8a271a41538cb255442cd3afd9df37f/419830462.pdf
    • https://www.shopveriamici.com/wp-content/plugins/super-forms/uploads/php/files/q9la67qcbue7sopoake7sj2d3n/10099231403.pdf
    • https://www.die-umzugsfabrik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611f9db40f00a---54060530829.pdf
    • http://www.morrisjones.co.uk/EditorImages/file/56565503802.pdf
    • http://jyotiacademicpress.org/uploads/file/vaxikewufedigag.pdf
    • https://sjalikave.hu/pictures/file/39945698071.pdf
    • http://busangh.com/attfile/fckimg/file///2021070621139_466653864.pdf
    • https://www.perfumista.co.uk/wp-content/plugins/super-forms/uploads/php/files/3d288623f632ecf41a427039abb5e8cc/fedumi.pdf
    • http://jamalcar.com/userfiles/file/fonemesamezirotajomo.pdf
    • http://reclaimsplus.com/wp-content/plugins/super-forms/uploads/php/files/8f4dcc390f7925f1064d0a19d00d6312/tonarapuxesasogow.pdf
    • http://valleypainclinic.org/userfiles/file/10435769009.pdf
    • http://heilpraxis-pankow.de/wp-content/plugins/formcraft/file-upload/server/content/files/160dde9a7c288b---vovoligov.pdf
    • https://condicionamentofisico.com/arquivos/file/6569177830.pdf
    • http://shuimotongyuan.com/userfiles/file/mizorewoxewonapegovegab.pdf
    • http://thucphamchucnangmy.vn/uploads/files/lewojifileruvifikugitar.pdf
    • http://citysuji.com/ckfinder/userfiles/files/26233514576.pdf
    • http://www.masozilina.sk/ckfinder/userfiles/files/49795264340.pdf
    • 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_off0000b582.bin
7049a995d8f11abe45f8ba62dc6f990885a980f99305ab6999954c036e02dd55
pdf-font-stream PDF embedded font (sfnt) at offset 0xB582 16620 bytes
font_01_sfnt_off0000e05d.bin
b4a76535f83a83552bd696a83741f8574c98f574b30384549562be2c7fddac30
pdf-font-stream PDF embedded font (sfnt) at offset 0xE05D 11100 bytes
font_02_sfnt_off0000f98c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF98C 16792 bytes