Malicious PDF — malware analysis report

Static analysis result for SHA-256 a2421aa8cd8e16a1…

MALICIOUS

PDF

84.0 KB Created: 2021-09-13 20:44:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 044a787da68eccc51f99c0959927c49c SHA-1: 9d6e67d299054576f0fada12a8defb9be5c096ae SHA-256: a2421aa8cd8e16a151b34fd2e0a7be0db3b3013cecfa6deabae7e1e2080e8369
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which are hosted on compromised CMS platforms or disposable hosting, indicating a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution. The embedded JavaScript is a common technique for executing malicious code or redirecting users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 7

  • 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.
  • 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 https://synerhu.ru/uplcv?utm_term=samsung+galaxy+s4+latest+version PDF link annotation
    • https://vietnaminsight.biz/ckfinder/userfiles/files/koxazetoxofa.pdfIn PDF document text
    • http://dighakanchaninternational.com/FCKeditor/file/binetinizavezabod.pdfIn PDF document text
    • https://bio86.net/userfiles/fichiers/10918276558.pdfIn PDF document text
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/6c2467f0cd0268fbe2d585fc2eb01805/lisidoja.pdfIn PDF document text
    • http://thewesternmist.com/userfiles/file/vegebo.pdfIn PDF document text
    • https://adikketiga.com/contents/files/30382512563.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/68599163710.pdfIn PDF document text
    • http://agataklimowska.pl/userfiles/file/70885659229.pdfIn PDF document text
    • https://cpc-serbia.org/js/files/dewiwujili.pdfIn PDF document text
    • http://jljemc.com/upload/files/97148360450.pdfIn PDF document text
    • https://thaiahpa.com/flash/files/63781112372.pdfIn PDF document text
    • https://soenen-pneus.com/upload/file/gidopesugo.pdfIn PDF document text
    • http://tartak-monis.pl/tartak/images/file/13675363103.pdfIn PDF document text
    • http://raduzhniy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136694d5d4c5---rikunaremulixesamitexu.pdfIn PDF document text
    • https://autonoleggioassereto.com/file/wetelunesi.pdfIn PDF document text
    • http://sarljarry.com/userfiles/file/47842324180.pdfIn PDF document text
    • http://shriadinathbank.com/uploads/84056400829.pdfIn PDF document text
    • http://tyros-club.de/userfiles/file/63765652693.pdfIn PDF document text
    • https://congchungnguyenlieu.vnpec.xyz/uploads/files/80478657352.pdfIn PDF document text
    • https://cli-kh.com/uploads/files/202109130027301241.pdfIn PDF document text
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e2c1dbdef5---5235304371.pdfIn PDF document text
    • http://aluminial.pnh.pt/js/ckfinder/userfiles/files/86857451604.pdfIn PDF document text
    • http://objets.immoweiss.lu/userfiles/files/5257957525.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_off0000e23f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE23F 17696 bytes
SHA-256: 82e2c728e134275449373bd0a822f1fae03f1b2ff08d2f17e8b1701a49f52c03
font_01_sfnt_off00011051.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11051 10984 bytes
SHA-256: 0e38e8524329bf3cbe9286acb871876205c685114548163a0d3b0fbace3590b1
font_02_sfnt_off000129e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129E9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1