Malicious PDF — malware analysis report

Static analysis result for SHA-256 501fe8a6ec3d3cfd…

MALICIOUS

PDF

82.7 KB Created: 2021-09-05 22:27:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 801b91a6eb174082d5978050029c246e SHA-1: 66485d41e2d6858b44f4b70d3405c4f38bbde474 SHA-256: 501fe8a6ec3d3cfd7f4914c36fc9989480a72c2718d17d3dcf97061a8d0a0813
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs that point to various websites, many of which are hosted on compromised WordPress installations. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and unreadable, suggesting it's not intended for direct user interaction but rather to host the malicious links.

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://cructi.ru/uplcv?utm_term=free+all+file+to+pdf+converter+software
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bfc0f7d5a02---10134829350.pdf
    • https://penzionradvanice.cz/res/file/34250006226.pdf
    • http://www.elitagida.com.tr/wp-content/plugins/super-forms/uploads/php/files/3dbnrr2do6t4g2rh0u4ch819u4/63386525717.pdf
    • http://greenhousehotel.vn/uploads/image/files/58877367844.pdf
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077f866e36f6---kafasadexopoketokoji.pdf
    • https://baileyelectrical.services/wp-content/plugins/super-forms/uploads/php/files/8fpcjrc1td7eipdqddfvppn3hr/14556889105.pdf
    • https://wagaskar.com/media/nasarimitonobojore.pdf
    • https://bleikss.com/userfiles/file/31526036512.pdf
    • https://www.micron21.com/application/third_party/ckfinder/userfiles/files/rebusupar.pdf
    • http://abogadosaguilar.com/ckfinder/userfiles/files/vujojer.pdf
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/1607d7c46b1776---70243597428.pdf
    • http://inwallendorf.de/userfiles/file/71688415465.pdf
    • https://33mobility.net/uploads/files/senopanog.pdf
    • https://sellos-mecanicos.com/wp-content/plugins/super-forms/uploads/php/files/85a38feb37d8110e63ff2da64c01cddc/45918972097.pdf
    • http://giadinhlaurenso.org/upload/files/54368121661.pdf
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610332e7b5eb3---suzamuzakeni.pdf
    • https://sambelteri.com/contents//files/34675432424.pdf
    • http://zhengfutz.com/v15/Upload/file/20217151411423739.pdf
    • http://izumrud38.com/ckfinder/userfiles/files/vofalusuboritez.pdf
    • https://bonpetsupply.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075067510813---24387502846.pdf
    • http://dok-vo.ru/userfiles/file/68226674497.pdf
    • http://iburgisidimarsala.eu/userfiles/files/figekidigowatazopox.pdf
    • http://boletin.alicantehosteleria.com/lib/ckfinder/userfiles/files/21788375905.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_off0000ddad.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDDAD 16792 bytes
font_01_sfnt_off0000f5bf.bin
c465ba0e2a35a8dc2aa979d7356c43105a51d61449554346f88c4fb990fd63f8
pdf-font-stream PDF embedded font (sfnt) at offset 0xF5BF 18084 bytes
font_02_sfnt_off00012422.bin
82de506c736b31595007667835ea6a6cb0a857c382c28996258a9978546c3864
pdf-font-stream PDF embedded font (sfnt) at offset 0x12422 10744 bytes