Malicious PDF — malware analysis report

Static analysis result for SHA-256 673cdf02c664aace…

MALICIOUS

PDF

71.2 KB Created: 2021-09-21 17:14:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f9b2078e0de73d013815e336fda228fd SHA-1: 2d36a338b6742bf94240cc42e29c8f1fe4b501d7 SHA-256: 673cdf02c664aace941686ff0f78385329235bd63c0a2a382cb4e94fe650ddf6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, indicating a link farm designed for malicious redirection. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://crewmak.ru/uplcv?utm_term=kinemaster+pro+pc
    • https://31app.com/userfiles/file/kujavolenakimujobofix.pdf
    • https://tavio.ru/files/file/71744259601.pdf
    • http://stinpo.com/ckfinder/userfiles/files/30204449187.pdf
    • http://arohitourandtravels.com/userfiles/file/gowabunufivem.pdf
    • http://divorce-difficile.fr/userfiles/file/62554187394.pdf
    • http://lumieye.com/userData/ebizro_board/file/76839138551.pdf
    • http://pp-aqua.com/userfiles/files/91111566038.pdf
    • http://strojsteel.cz/webpagebuilder/ckfinder/userfiles/files/serazuk.pdf
    • http://www.caslyn.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16137fb4337e52---revaroxiduzojinatezut.pdf
    • https://greshamgilessalon.com/wp-content/plugins/super-forms/uploads/php/files/186e7db04af2e90f6d67b45f2cde1cab/10362863627.pdf
    • https://alquimia.in/admin/fckeditor/editorfile/65176160910.pdf
    • https://www.edm-medical.net/ckfinder/userfiles/files/zizosabanokajopumado.pdf
    • https://vialivonica.eu/userfiles/files/82895644149.pdf
    • https://nucamsa.es/userfiles/files/1399314241.pdf
    • http://5mal4.de/moneyvidya/web/images/userfiles/file/guzidunolomumex.pdf
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613c67b88ab8a---73145635176.pdf
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/161476797c6ad5---budizofaw.pdf
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16148b8d56f25f---96336194027.pdf
    • https://shibbirs.com/media/files/foxemukalokogowokidesakot.pdf
    • https://photographerin.agency/wp-content/plugins/super-forms/uploads/php/files/h07sp3jvgd75cid74t7q7tfuk6/velibaz.pdf
    • http://de.ruben.pl/ckfinder/userfiles/files/samuzigizemef.pdf
    • http://greenld.com/userfiles/jisukunemurijeje.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_off0000b64b.bin
9d9ec20a14bca1fc85a2913f894ce413ab6253fc374146809c3a6d4301f6799a
pdf-font-stream PDF embedded font (sfnt) at offset 0xB64B 10480 bytes
font_01_sfnt_off0000ce16.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCE16 16792 bytes
font_02_sfnt_off0000e628.bin
611fad7d77377a3b927e356a55ef856249df2ee367e617178981000bda6466be
pdf-font-stream PDF embedded font (sfnt) at offset 0xE628 16312 bytes