Malicious PDF — malware analysis report

Static analysis result for SHA-256 86d8b5883607c7c8…

MALICIOUS

PDF

80.5 KB Created: 2021-09-16 15:37:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3a18ad7e494718a5348f28caa6c09d7f SHA-1: 43036e7eca96c5201b496bf4d6fd7fa9921d0c6c SHA-256: 86d8b5883607c7c8e77cad86bb252dfa30613c00fc9597a4f25b4bd35e5d0ef1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which are part of a link farm hosted on compromised or disposable domains. Heuristics indicate a 'PDF link farm' and 'compromised CMS upload link farm', suggesting the document's primary purpose is to redirect users to external sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://krisoc.ru/uplcv?utm_term=whistle+tone+for+android
    • http://nissanotogovap.com/uploads/images/files/51342606100.pdf
    • http://assessmentinsight.com/ckfinder/userfiles/files/67622978723.pdf
    • http://humanitool.ru/userfiles/file/kebitaxupul.pdf
    • http://musorcentrum.hu/files/article/file/bolopojimasik.pdf
    • http://studiogalata.it/userfiles/files/varamuzilogor.pdf
    • https://ysh.my/userfiles/file/94806270431.pdf
    • http://coytex.net/ckfinder/userfiles/files/sekejupaxodisuvetuli.pdf
    • http://interstyle.org/content/xuploadimages/file/dawanesenos.pdf
    • https://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/78167de0214e9820c467f2b92b47b58a/31283197380.pdf
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140ba4778e91---lemotisadepovadido.pdf
    • http://fixafilm.se/userfiles/file/14225948122.pdf
    • https://happyjourney.webtrails.in/ckfinder/userfiles/files/magokimurofib.pdf
    • https://profitaler.com/UserFiles/file/4987265181.pdf
    • https://westhigienia.hu/editor_up/xadasurad.pdf
    • https://www.ojchamber.com/ckfinder/userfiles/files/dotojaf.pdf
    • http://bkmarine.net/ckfinder/userfiles/files/1630612684.pdf
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130a67b36531---25934344014.pdf
    • http://indemo.pl/Image/files/matojonegamamanutoxawu.pdf
    • https://www.iieng.org/editor/ckfinder/userfiles/files/gadavevadanegadixiwofeda.pdf
    • http://abwfinlay.com/uploads/files/95722479281.pdf
    • https://leicht-spb.ru/wp-content/plugins/super-forms/uploads/php/files/fdf9d95b489ee89b124d12b61214c461/bokomiguxeliwus.pdf
    • http://massarentearchitettura.com/userfiles/files/23654754128.pdf
    • https://devcons.org/uploads/userfiles/files/gozenamunu.pdf
    • http://xn--12cbg9dihj7egda2g6a7dceb1d2cp4nvgf4f.com/datas/files/siminudenemoj.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_off0000d0a7.bin
85cf79439e0d3f4815f4499d8895bf71388451bb9f90af3dcf0deac595fae811
pdf-font-stream PDF embedded font (sfnt) at offset 0xD0A7 19688 bytes
font_01_sfnt_off000104ba.bin
5ca580fd57fe1b2ef3e7f2ae55c6196fbd197a6ac699db2b2ab16c889bc08e19
pdf-font-stream PDF embedded font (sfnt) at offset 0x104BA 10444 bytes
font_02_sfnt_off00011c5e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11C5E 16792 bytes