Malicious PDF — malware analysis report

Static analysis result for SHA-256 c6cba3c73b9d79b7…

MALICIOUS

PDF

70.3 KB Created: 2021-09-24 19:12:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 14203d15537c58a824075cdbbb3c5e72 SHA-1: 2b3b31fdaae94ffdc6fe2ed42eafcdfbdb1afaf1 SHA-256: c6cba3c73b9d79b73b35e42c1024182fcef3c18696346595e595dde3e696b804
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm with numerous external URIs pointing to disposable hosting, suggesting an attempt to distribute malicious content or phish users. The presence of embedded JavaScript, though not explicitly detailed in the provided evidence, is a common vector for such attacks within PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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=download+bookworm+deluxe PDF link annotation
    • https://sportsslife.net/upload/ckfinder/files/gexevupidopovoro.pdfIn PDF document text
    • http://supair-lux.hu/ckfinder/userfiles/files/94168580133.pdfIn PDF document text
    • http://vagtteam.com/userfiles/Files/wuwexarizonugoj.pdfIn PDF document text
    • https://rimsball.com/ckfinder/userfiles/files/56781179069.pdfIn PDF document text
    • https://xebecdesign.com/xebec/userfiles/file/90012705466.pdfIn PDF document text
    • http://yaqeen-eg.com/userfiles/file/92024805836.pdfIn PDF document text
    • http://darec.sk/files/files/mubesifiwafaxerimutinimap.pdfIn PDF document text
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/mcfje4dgql6ljgf22sqojtu53u/pewol.pdfIn PDF document text
    • http://ayurveda-shiatsu-nice.com/upload/files/tujajizowozexewoxilenuluj.pdfIn PDF document text
    • http://gz-theoutfit.com/UploadFiles/FCKeditor/20210921081430.pdfIn PDF document text
    • https://seeandhearbetter.ie/img/shop/contents/binejadofopexe.pdfIn PDF document text
    • http://kemmurad.com/webroot/img/files/kefazi.pdfIn PDF document text
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613feaba9b9bc---18001355719.pdfIn PDF document text
    • https://dafelia.com/files/41863638617.pdfIn PDF document text
    • https://alienaquatics.com/home/gb/public_html/ckfinder/userfiles/files/57992647043.pdfIn PDF document text
    • https://hanedantoptan.com/upload/files/gutaxedofasibuxuziruj.pdfIn PDF document text
    • https://portecitadelle.portecitadelle.ca/ckfinder/userfiles/files/jowokal.pdfIn PDF document text
    • https://xn--80apefbdm9ah5g.xn--p1ai/userfiles/60251137136.pdfIn PDF document text
    • http://pjteam.hu/uploads/gujerazam.pdfIn PDF document text
    • https://www.frontiermyanmar.com/sites/all/libraries/ckfinder/userfiles/files/97838668952.pdfIn PDF document text
    • https://friendsofmultisport.com/ckfinder/userfiles/files/33529344119.pdfIn PDF document text
    • https://dubigroup.com/admin/fckeditor/editor/filemanager/connectors/upload/file/8525224336.pdfIn PDF document text
    • http://borneneskontor-landsforening.dk/userfiles/file/rixaxalese.pdfIn PDF document text
    • https://doan295doson.vn/namthuan/images/news/files/bawojakodolube.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_off0000b16a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB16A 10572 bytes
SHA-256: db6cfbf06e7c0cfa5dda8bfacb40eee44370ed98510e17819ed294b9f9123469
font_01_sfnt_off0000c98b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC98B 16816 bytes
SHA-256: 857dd135d577e63f907945e7e72bbc4ccceebbb053ce79303444ec4e11c6747c
font_02_sfnt_off0000f3bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3BC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1