Malicious PDF — malware analysis report

Static analysis result for SHA-256 c21d462b669c8502…

MALICIOUS

PDF

69.9 KB Created: 2021-09-28 13:47:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 280846db0784032f9f98a7d650ef8efd SHA-1: 73f04f8792e1fe4e24ed0e5e03ed013a290b751e SHA-256: c21d462b669c850289ed034896a0c9e55b2f74ebe9319bce43a2dce84c9810b6
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, a common technique for malicious PDFs. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the document is a link farm on disposable hosting, suggesting a phishing or scam attempt. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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 http://nenkin-t.com/upload_img/ck/files/75739466190.pdf In PDF document text
    • http://jadever.vn/Images_upload/files/muwel.pdfIn PDF document text
    • http://tc-muehlacker.de/data/tcmuehlacker/userfiles/file/nulovumidonuva.pdfIn PDF document text
    • http://xn----7sbakn3aoflleitf3m6a.xn--p1ai/userfiles/file/jexumunipotivefefujumu.pdfIn PDF document text
    • https://evrenmentese.com/upload/ckfinder/files/pabevasisazaribo.pdfIn PDF document text
    • http://bratislava.topenglish.sk/app/webroot/gallery/files/movirixawefesukavumefe.pdfIn PDF document text
    • http://incomsistema.ru/ckfinder/userfiles/files/55652557758.pdfIn PDF document text
    • https://maytinhdalat.vn/images/uploads/files/53135873617.pdfIn PDF document text
    • http://esistore.com/userfiles/file/tijakofemuzikotakikumonud.pdfIn PDF document text
    • http://ashole.hu/UserFiles/File/gogikoramopinulugofogexus.pdfIn PDF document text
    • http://hanshintech.net/data/file/pakujegix.pdfIn PDF document text
    • http://cattaneoarchitetti.it/userfiles/files/fatogoruxererava.pdfIn PDF document text
    • https://www.playitdirect.ca/ckfinder/uploadfiles/files/luwipod.pdfIn PDF document text
    • https://nicklason.se/ckfinder/userfiles/files/96694412380.pdfIn PDF document text
    • https://ichapps.com/ichapps/ckeditor-ckfinder-integration/uploads/files/56647862612.pdfIn PDF document text
    • http://due.pt/js/ckfinder/userfiles/files/legunojubipegexogavafimi.pdfIn PDF document text
    • http://szjwwj.com/userfiles/file///50831822534.pdfIn PDF document text
    • https://phase1acoustics.com/wp-content/plugins/formcraft/file-upload/server/content/files/161467e4831c32---55245639223.pdfIn PDF document text
    • http://getvisa.ru/images/File/12145370728.pdfIn PDF document text
    • https://luxesystem.site/js/ckfinder/userfiles/files/84809095602.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/1614c632a776a2---nubibudedarijir.pdfIn PDF document text
    • http://german-ex.com/images/blog/file/77276418830.pdfIn PDF document text
    • http://www.cenlajobinator.com/siteuploads/editorimg/file/vejife.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=what+is+the+best+gun+in+warzonePDF link annotation
    • 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_off0000b04c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB04C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c85e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC85E 16276 bytes
SHA-256: 1d01e26d238fd8e340d8ec16e8f4fb4e0888f8560c1442ac0a2bd58f760d9ae9
font_02_sfnt_off0000f18b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF18B 10720 bytes
SHA-256: 29f4638758a254c686db69f6a4f732b027620d104e5ef485667e4cb3cf40e631