Malicious PDF — malware analysis report

Static analysis result for SHA-256 21b881035847f308…

MALICIOUS

PDF

79.6 KB Created: 2021-09-14 08:54:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 5e6dd56c9a904b99f9e772bed956f30a SHA-1: ee753245220cbbaa9a6ce6a493575aae58098917 SHA-256: 21b881035847f308fa4b13b132e24cdcd5f51ecbc5a75652c2dbf7c5e7b2f2da
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many hosted on compromised WordPress sites or disposable domains, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, but the presence of multiple URLs and the PDF structure point towards an attempt to lure users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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 https://allytemp.ru/uplcv?utm_term=nba+2k19+download+ppsspp PDF link annotation
    • https://patc.fr/imagesfile/63506613190.pdfIn PDF document text
    • https://afanasyev-design.ru/wp-content/plugins/super-forms/uploads/php/files/5f892a7e6ed711d5875ce9b73f37de6b/buwomepejaxam.pdfIn PDF document text
    • http://snnet.kr/board_pds/fckeditor/2021/09/file/89569317435.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/bmg51ovuonni34l3kkkj99pj64/9832450051.pdfIn PDF document text
    • https://www.tri-or.fr/tri-or/ckfinder/userfilesfiles/memadet.pdfIn PDF document text
    • http://fixafilm.se/userfiles/file/51062678567.pdfIn PDF document text
    • http://printrun.nl/userfiles/files/saxojopitizitodawikatar.pdfIn PDF document text
    • http://bukharaatlanta.com/sites/default/files/file/rojoxobukifenowoz.pdfIn PDF document text
    • http://lgassociates.in/uploads/buwaloz.pdfIn PDF document text
    • http://mabifitness.it/userfiles/files/jitefunefusu.pdfIn PDF document text
    • http://grappin-annat-como.com/userfiles/grappin-annat-como.com/file/berow.pdfIn PDF document text
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c7d8305ca4---zubib.pdfIn PDF document text
    • http://vers-ma.de/userfiles/file/55816567238.pdfIn PDF document text
    • https://airshow-bg.com/file/suberujesolixedupar.pdfIn PDF document text
    • http://ciaomamma.hu/editor_up/liladelun.pdfIn PDF document text
    • https://virker-ikke.dk/files/47769681890.pdfIn PDF document text
    • https://renfrewareahealthvillage.ca/ckfinder/userfiles/files/58693020913.pdfIn PDF document text
    • http://skupka54.ru/upload/m/vilukerafomunexovapemibow.pdfIn PDF document text
    • http://balassalaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/xakazepi.pdfIn PDF document text
    • http://ayhancevik.com/images_upload/files/55869927182.pdfIn PDF document text
    • http://bsl-trans.ru/admin/ckfinder/userfiles/files/fonete.pdfIn PDF document text
    • http://studiotecnicolari.it/userfiles/files/18101317725.pdfIn PDF document text
    • http://xn----7sbabaajmdfbk3ddf3azka3b6a2r.xn--p1ai/ckfinder/userfiles/files/bugul.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_off0000d0f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD0F8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e90a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE90A 18244 bytes
SHA-256: 4f8b75c5b425c47511d962f007faf20fc0f286a902c57561694ecb2113d1843f
font_02_sfnt_off00011894.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11894 10600 bytes
SHA-256: 063549be9d80fd29b4a3c6d8501124ae69ef78add95a0fb88c2a57e0187f890c