Malicious PDF — malware analysis report

Static analysis result for SHA-256 33936bd5e87bd2b8…

MALICIOUS

PDF

79.6 KB Created: 2021-09-11 11:08:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 885b7e7dd88ed4263747ea1ebdf71142 SHA-1: baa931b5bacb8c2ec458b5833d9562018f2fa7ec SHA-256: 33936bd5e87bd2b86b1c488d40b55fbda0893031f905401cbd3f32c27735c28c
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to distribute malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware delivery through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

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=jogos+apk+e+data PDF link annotation
    • http://rinsacars.com/files/others/lubitom.pdfIn PDF document text
    • https://mpressivelabels.com.au/application/third_party/ckfinder/userfiles/files/zimidipu.pdfIn PDF document text
    • http://ergakiland.ru/files/files/sopirozununupuvo.pdfIn PDF document text
    • http://jmk.kr/ckfinder/userfiles/files/87445314102.pdfIn PDF document text
    • http://ratchee.com/ckfinder/userfiles/files/91334980711.pdfIn PDF document text
    • https://kitapkaplama.com/upload/ckfinder/files/84457933807.pdfIn PDF document text
    • http://jr-bang.com/uploadfiles/20210907131825.pdfIn PDF document text
    • https://www.gryf-wet.pl/ckfinder/userfiles/files/gasazozekokisabadoravokit.pdfIn PDF document text
    • https://darshanam.com/ckfinder/userfiles/files/23009700457.pdfIn PDF document text
    • http://yameitecl.com/ckfinder/userfiles/files/20210902_123411.pdfIn PDF document text
    • https://bankubezpieczen.pl/userfiles/file/33227415753.pdfIn PDF document text
    • https://binarbaidfabrication.com/public_html/userfiles/file/20197573776.pdfIn PDF document text
    • http://gaziogluenerji.com/images_upload/files/32493977320.pdfIn PDF document text
    • http://chukysovin.com/img-svc/files/60909134583.pdfIn PDF document text
    • https://kuraniterbiye.com/resimler/files/fovuvulatozoteralive.pdfIn PDF document text
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613491e061273---77017828571.pdfIn PDF document text
    • https://ice-group.pl/userfiles/file/72111872314.pdfIn PDF document text
    • http://culbertsonlawyer.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/22064269416.pdfIn PDF document text
    • https://psihodesk.ro/ckfinder/userfiles/files/wimupuka.pdfIn PDF document text
    • http://hzbmsj.com/images/upload/File/9374174545.pdfIn PDF document text
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a699878fc9---remogudegopirazutabora.pdfIn PDF document text
    • http://herfon-machinery.com/images/ckfinder/files/20210910123241.pdfIn PDF document text
    • https://natatourism.com/userfiles/files/mewejezarufuguwozugosu.pdfIn PDF document text
    • http://studiopol.it/userfiles/files/86812437782.pdfIn PDF document text
    • https://sunnyrosesschool.com/userfiles/file/tixin.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161398780b3cfc---gopemelufedufetinobete.pdfIn PDF document text
    • https://aspirans.com/files/file/45800804338.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_off0000d3b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3B1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ebc3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBC3 17776 bytes
SHA-256: 7731065375f3eee2e704dce3636305e262b8adbb99bbc5f974c8a89e215b5ba9
font_02_sfnt_off00011a38.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A38 10308 bytes
SHA-256: 5c9a880d7e8d5f094f314acd4d54b8138fc1c7a2da7ae945f00b37fae8aa16ee