Malicious PDF — malware analysis report

Static analysis result for SHA-256 41b50835430cccae…

MALICIOUS

PDF

81.4 KB Created: 2021-09-17 00:59:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 0d964000ff3b4042ace77d0aea2f839f SHA-1: 8dc06d70818a2fc7c654ba67810d1c7867bd651f SHA-256: 41b50835430cccae93df70033ba9f9d9545f84db7064cf88d9590b472738153c
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier, indicating a phishing or trojan threat. It contains numerous embedded URLs, many of which point to compromised WordPress upload directories or disposable hosting, suggesting an attempt to distribute malicious content or phish users. The primary function appears to be acting as a link farm to redirect unsuspecting users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://amatnieks.com/pictures/image/68466360004.pdf In PDF document text
    • https://rcot.org/userfiles/file/wexolilokizuwuranab.pdfIn PDF document text
    • http://shortguycentral.com/ck_uploads/files/87415489918.pdfIn PDF document text
    • http://bjerkelunden.org/content/files/userfiles/file///bipex.pdfIn PDF document text
    • https://yocarbroker.com/upload/ckfinder/files/73063244989.pdfIn PDF document text
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16138d7e631003---52749459567.pdfIn PDF document text
    • https://editionsitaliques.com/userfiles/file/32468274731.pdfIn PDF document text
    • https://www.huaikrachaohospital.go.th/assets/global/lib/ckfinder/userfiles/files/baduku.pdfIn PDF document text
    • https://drrajanmahtani.com/userfiles/files/14603021544.pdfIn PDF document text
    • http://gewald.ru/content/Files/redim.pdfIn PDF document text
    • https://debcopharma.com/userfiles/file/panalurefodalodekoguv.pdfIn PDF document text
    • http://mdknoodles.co/uploads/files/fabitukipimofitemigete.pdfIn PDF document text
    • http://rilta.net/userfiles/files/69610579782.pdfIn PDF document text
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16141912ad9719---zowomeja.pdfIn PDF document text
    • http://vp-dmsh.ru/admin/ckfinder/userfiles/files/61531476407.pdfIn PDF document text
    • https://printsolutions.printsolutions.bg/uploads/wysiwyg/files/61903217972.pdfIn PDF document text
    • https://www.luthier-auxerre.fr/ckfinder/userfiles/files/42551695188.pdfIn PDF document text
    • http://studiogaleazzo.eu/userfiles/files/8077945490.pdfIn PDF document text
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/16136c4d6365b6---47327242334.pdfIn PDF document text
    • http://salonorganica.ru/upload/files/29635427491.pdfIn PDF document text
    • https://voicelux.ru/wp-content/plugins/super-forms/uploads/php/files/35103631b2dc932408af0bc555f893fe/28550582020.pdfIn PDF document text
    • http://lightofislamonair.org/uploads/files/87843531013.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=harry+potter+and+the+sorcerer%27s+stone+pdf+downloadPDF link annotation
    • https://cakamuzejs.riga.lv/ckfinder/userfiles/files/97911925101.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_off0000d795.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD795 10848 bytes
SHA-256: 8ecb981fac6a365f15e4c23b74b088fb382c3699ef276b81e3eade2d1f38dfdf
font_01_sfnt_off0000f0ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0AB 18076 bytes
SHA-256: 24f9ec645923cb16f7e170f715bfb3855e0a445c065c0f85b70db2d10a255ea7
font_02_sfnt_off00011f83.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F83 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1