Malicious PDF — malware analysis report

Static analysis result for SHA-256 c983cf8b3d83d814…

MALICIOUS

PDF

85.4 KB Created: 2021-09-01 18:35:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: f5c9a3ff194933bfd6056c7dfa086d7b SHA-1: 42305ea3b4517d6e88582ffd1812bd2a06ff7179 SHA-256: c983cf8b3d83d814866479808fa66dccd59f82aa6286dd863dd8a6c85f23896f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous external URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm or phishing attempt. ClamAV detected this file as Pdf.Phishing.Trojan, and ML classifiers also flagged it as malicious. The presence of external links suggests an attempt to redirect users to malicious sites, potentially for credential harvesting or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9919

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://pistant.ru/uplcv?utm_term=how+to+select+and+change+color+in+photoshop PDF link annotation
    • http://www.firstpages.eu/app/webroot/files/userfiles/files/34149474138.pdfIn PDF document text
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/4mgcinvf3pimio9ek3is5kkpk4/teluwotare.pdfIn PDF document text
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/16073f0f334e4c---44396654450.pdfIn PDF document text
    • http://solemarservizi.it/userfiles/files/fajobirikokixojo.pdfIn PDF document text
    • http://mjacz.cz/soubory/files/52647530594.pdfIn PDF document text
    • http://studiomarazzi.eu/userfiles/files/79115804010.pdfIn PDF document text
    • https://ssvacancy.com/ckfinder/userfiles/files/nuritudi.pdfIn PDF document text
    • https://bartonsteel.com/tony/barton/ckfinder/userfiles/files/20530531974.pdfIn PDF document text
    • https://motionslam.com/wp-content/plugins/super-forms/uploads/php/files/dfefc364960c74c16a9f2fd2880b2c84/xuwukerif.pdfIn PDF document text
    • https://gangwontaxi.com/FileData/ckfinder/files/20210810_1782BAD516E5DCC9.pdfIn PDF document text
    • https://lynnesnaturaltreats.com.au/wp-content/plugins/super-forms/uploads/php/files/77ee26153288c065a7303309d3b57eb6/kogevupevokumisezoga.pdfIn PDF document text
    • http://zzfcw.com/file/fkimg/file/51534316396.pdfIn PDF document text
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d3794af7ab---ruxekonifumuborifilotel.pdfIn PDF document text
    • http://eot.mn/uploads/userfiles/files/7365687212.pdfIn PDF document text
    • http://bibrka-school.org.ua/ckfinder/userfiles/files/funijijatuzil.pdfIn PDF document text
    • http://bocghebinhduong.com/media/ftp/file/99234826829.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160be0a5f03775---63458352651.pdfIn PDF document text
    • https://kurek-rowery.pl/user_pict/file/163272424.pdfIn PDF document text
    • http://fslawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/gubosepofekap.pdfIn PDF document text
    • https://www.corridar.com/wp-content/plugins/super-forms/uploads/php/files/5ge5v67r8fm9jfkflgvchl7fdi/80428295147.pdfIn PDF document text
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/1607b63534040a---patadupexozisidoxubisiz.pdfIn PDF document text
    • http://donkaew-furniture.com/ckfinder/userfiles/files/xerogupujirukusotipa.pdfIn PDF document text
    • https://papiratisk.cz/soubory/wosipojuwazuxa.pdfIn PDF document text
    • https://muguet.fr/sites/default/files/file/47278663567.pdfIn PDF document text
    • https://gazelletr.com/userfiles/files/13480782542.pdfIn PDF document text
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f07cf754832---biwabanule.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_off0000e807.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE807 17648 bytes
SHA-256: 74cfa31c35dff45a7a4207f80154057edbcefa2cc047b390b08eaa4af9eaea55
font_01_sfnt_off00011600.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11600 10872 bytes
SHA-256: 10461209709e336d400f843fd9e7cd9ad2f3a43c473df2c65495e97595a66e33
font_02_sfnt_off00012edf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12EDF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1