Malicious PDF — malware analysis report

Static analysis result for SHA-256 33e4fdd479c94db8…

MALICIOUS

PDF

86.6 KB Created: 2021-08-30 07:25:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: b6a4a264bc0410bcd6d1dd38d3f481ae SHA-1: 8a81a6a6a5da703b82a899f7aae837cf6501b191 SHA-256: 33e4fdd479c94db8f936b7698a470f3f9b7be6ed63f28a0d391b27c7fa283f6c
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised CMS upload directories and disposable hosting, indicative of a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the extensive use of external URLs is the primary attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://inwebjor.ru/uplcv?utm_term=related+to+nursing+diagnosis PDF link annotation
    • http://s8radziejowice-paszkow.pl/userfiles/file/11860537954.pdfIn PDF document text
    • http://sacoorhealth.pt/site/upload/file/pazovapepamolo.pdfIn PDF document text
    • https://www.popcaffe.it/wp-content/plugins/super-forms/uploads/php/files/10ebcf3a7e624c0b41bc80facf0b0c5e/bubakevisin.pdfIn PDF document text
    • http://blueyee.com/upload/file/110826329759.pdfIn PDF document text
    • https://ols.lighting/wp-content/plugins/super-forms/uploads/php/files/942e317fab150b15249dc86047c467a4/12830423675.pdfIn PDF document text
    • http://mikomisushi.com/uploads/files/burajoxole.pdfIn PDF document text
    • http://marasintl.com/public/ckfinderuploads/files/wenemetunosuzabiz.pdfIn PDF document text
    • https://polinagerz.ru/wp-content/plugins/super-forms/uploads/php/files/p9fcdo6ge21kdp2ofjsiaelbig/larowojitegepawajidokerix.pdfIn PDF document text
    • http://cantinachitarra.it/userfiles/file/fanuxosefobulefudamu.pdfIn PDF document text
    • https://foxtailmag.net/wp-content/plugins/super-forms/uploads/php/files/2f3abd3a3324d923a548854b0514c99d/65066274918.pdfIn PDF document text
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/16121ab585a8c7---dovajaxigibo.pdfIn PDF document text
    • https://investmentskillsgroup.com/images/userfiles/file/tovebidosubuxu.pdfIn PDF document text
    • http://hopkinshigh62.com/clients/7/77/7764523e397120ad9b09b1da26998858/File/5393875399.pdfIn PDF document text
    • https://dichvumayphoto.vn/webroot/img/files/gexozajikevojew.pdfIn PDF document text
    • http://christembassydocklands.org/wp-content/plugins/super-forms/uploads/php/files/efeb87c8b74cbe713bd99f310bd81fc4/kipilufipowapodapibetal.pdfIn PDF document text
    • http://apcmagon.com/userfiles/xuwajuson.pdfIn PDF document text
    • http://oticonshop.net/ckfinder/userfiles/files/16437823778.pdfIn PDF document text
    • https://singaporenotarypublic.com/wp-content/plugins/super-forms/uploads/php/files/d4c95d0b06c4fd81bd8b3cbc19dc4253/89392866688.pdfIn PDF document text
    • https://luxurytravel-show.com/wp-content/plugins/super-forms/uploads/php/files/62f482a502051b97fd8ea6e0b19ef9ff/52492724812.pdfIn PDF document text
    • https://www.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/16092b36a7a339---88309356379.pdfIn PDF document text
    • http://adaviestransportltd.com/userfiles/file/98006705376.pdfIn PDF document text
    • https://www.certificagreen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c296d094c6---82535291404.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/9otsilkjl2rgo18ifqjivrj5t7/foxekivokejebizajinibam.pdfIn PDF document text
    • http://vimbark.sk/editor_uploads/files/1650089372.pdfIn PDF document text
    • https://mehreganimaging.com/images/upload/files/sebexab.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_off0000eff8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFF8 10568 bytes
SHA-256: 6e2f72ca271af40fb2f3e2082a1c5c8564de3703595d994ae720e877c035239d
font_01_sfnt_off000107fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107FB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001200d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1200D 16788 bytes
SHA-256: d69b95f29091d85d88567c3d2a2e0606c43524dd0ea3bf693652cc822c6039c2