Malicious PDF — malware analysis report

Static analysis result for SHA-256 a86b0c3dceaebcf0…

MALICIOUS

PDF

116.6 KB Created: 2021-09-17 22:08:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: bdc81ed16f655a819c04cce1e715ede0 SHA-1: 030f43b9d56fd32da7d0617d9724064db981c317 SHA-256: a86b0c3dceaebcf0da7e2bf236230de126b6b7a72aa48350167c57c8a95959dc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of 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 structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9930

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://infrive.ru/uplcv?utm_term=kopia+zapasowa+android+na+komputerze
    • http://prtourusa.com/FileData/ckfinder/files/20210903_594F8EB1811DAA4C.pdf
    • https://wietsevoermans.nl/ckfinder/userfiles/files/50521837224.pdf
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/1614090f23da0a---bumevunemederajimolere.pdf
    • http://msslink.ru/userfiles/files/wuzifojatudezawaxev.pdf
    • https://sagarexpress.com/userfiles/file/176962964.pdf
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/9c00510cc24f5ffcd743f925f515ddcf/31187220767.pdf
    • http://karthikeyanjayaram.com/userfiles/file/navan.pdf
    • https://moma-restaurant.com/wp-content/plugins/formcraft/file-upload/server/content/files/161370a5d569b5---jisejelevasat.pdf
    • https://knurussian.kr/DATA/upload/files/202109151604049794.pdf
    • https://growmytruck.com/wp-content/plugins/super-forms/uploads/php/files/ebb38b9b0fa4a4c6721ab2884359ac4e/jedavimudemodajediboba.pdf
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/161300c9d3404f---dosarifokil.pdf
    • https://swotin.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136d1c75eb2d---10795937149.pdf
    • http://madiagranitosilano.it/userfiles/files/61517583360.pdf
    • http://www.s-prom.si/fileupload/file/nulofaradalodimufagodiw.pdf
    • http://mdtrend.hu/files/file/sopovifatola.pdf
    • https://gallerylingard.com/uploads/file/nazakikike.pdf
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1613384019ac18---29812477526.pdf
    • http://fuyu.010bi.com/ckfinder/userfiles/files/10867715339.pdf
    • https://www.grdr.org/paidel/ckfinder/userfiles/files/pijajarewewifu.pdf
    • https://zivotzaokny.eu/res/file/fekepafojivifabatexamo.pdf
    • https://himalayanwanderer.com/himalayan/userfiles/files/boxidibusudufonudado.pdf
    • http://esllearningbydesign.com/app/webroot/files/file/24088355903.pdf
    • http://naturpix.ch/cmsimages/file/45620128994.pdf
    • http://trust-law-firm.com/userfiles/file/20210916120610_460680451.pdf
    • http://jatechkj.pl/upload/fck/file/nezonepujeke.pdf
    • http://thedewakohchang.com/image/upload/File/4574100293.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_off000162f7.bin
80ef66207535a344e00b8522f6bbe0d97b03d928967a96f8d0e8a7b82f9559fe
pdf-font-stream PDF embedded font (sfnt) at offset 0x162F7 10836 bytes
font_01_sfnt_off00017c20.bin
7c0f7abc6f6e6f9a59db9205d1ed1955fe71e2164c95ae8699da8e0b88d078a5
pdf-font-stream PDF embedded font (sfnt) at offset 0x17C20 18400 bytes
font_02_sfnt_off0001aaf9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1AAF9 16792 bytes