Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ac31e263bfc6007…

MALICIOUS

PDF

82.7 KB Created: 2021-09-11 06:23:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 60024ad58cad83c8d43b7ebf36d45bf7 SHA-1: f900e6a54b4b54357e6643746ed9b3cdcfaa3dc9 SHA-256: 4ac31e263bfc6007fc8bbf2d26c3e96be088345e7e0ff7e6ef2d8acfafa68f17
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many hosted on disposable domains or compromised WordPress sites, characteristic of a link farm. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or SEO spam. While no scripts were explicitly extracted, the PDF structure and link farm behavior suggest it's designed to redirect users to potentially malicious content.

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://chcial.ru/uplcv?utm_term=ipad+pro+vs+samsung+s7+plus PDF link annotation
    • http://asiadomainstore.com/userfiles/file/47845872505.pdfIn PDF document text
    • http://www.hollyskauaicondo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613326867a2bf---buvulijojawawijefi.pdfIn PDF document text
    • https://fuze-pay.com/ckfinder/userfiles/files/64785488146.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/161373c1b297a6---folapekoxup.pdfIn PDF document text
    • http://uceng.net/_UploadFile/Images/file/suxonabusijeminivokojami.pdfIn PDF document text
    • http://rooptex.com/uploads/26638522391.pdfIn PDF document text
    • http://hide-bo.com/img/tmp/file/nonixet.pdfIn PDF document text
    • http://onlineticketreview.com/images/file/wenidaxu.pdfIn PDF document text
    • http://krukaiart.com/userfiles/files/wizeliziguzaxuxeguwibib.pdfIn PDF document text
    • http://www.medicellbank.com/userfiles/files/sexorevibapulilodekizes.pdfIn PDF document text
    • http://tainghe.vn/userfiles/file/xilinudi.pdfIn PDF document text
    • http://jljemc.com/upload/files/xuvojalugekalawawe.pdfIn PDF document text
    • http://gasasosong.com/upload/fckeditor/file/movuwajuxor.pdfIn PDF document text
    • http://ossokahve.com/upload/file/60327059822.pdfIn PDF document text
    • http://st-johnson.com/Uploadfiles/files/bivetawugabifededazixado.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137c273d9370---buxilizonokajivojisole.pdfIn PDF document text
    • http://chelseacarpet.com/ckfinder/userfiles/uploads/gexebo.pdfIn PDF document text
    • http://www.gamylai.vn/uploads/files/45651843848.pdfIn PDF document text
    • http://ersatzmonitor.de/userfiles/file/95175655573.pdfIn PDF document text
    • https://indiantiffin4me.com/nbloom/fckuploads/file/dageridazajixemudiwobir.pdfIn PDF document text
    • http://weorderfood.com/uploads/files/28003296356.pdfIn PDF document text
    • http://fceresources.com/ckfinder/userfiles/files/dasapaxedanuxuninapojor.pdfIn PDF document text
    • http://donateagift.eu/userfiles/file/sejanemamada.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_off0000deb4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEB4 17780 bytes
SHA-256: 2108c6edceb5f535173f9b5f8c1281928068df0bb29d1280201206ee404fb91c
font_01_sfnt_off00010ce1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CE1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000124f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124F8 10580 bytes
SHA-256: 85e8c6be5cc9762e25eeecbddd03e7341c14915f9ee585004edb4a2dfa88995c