Malicious PDF — malware analysis report

Static analysis result for SHA-256 b716903461b9442d…

MALICIOUS

PDF

82.6 KB Created: 2021-09-08 08:00:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 4cd4e73037e7201e291b38305fc62959 SHA-1: e005b62ed0950f66f875f65c998d2945bc0df8d4 SHA-256: b716903461b9442d33546f9c3af1c1808863e49a60cdc58e3092e6ca636e2170
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress upload directories, indicating a link farm designed for SEO manipulation or phishing. ClamAV detection and ML classification confirm its malicious nature, likely as a phishing or trojan delivery mechanism. The document body is heavily obfuscated and unreadable, providing no direct user-facing content, but the presence of external URIs and compromised CMS uploads strongly suggests a malicious intent to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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 http://alternativefitness.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1611662ea4bdad---dotetufufezidu.pdf In PDF document text
    • https://trungtammatnamviet.vn/upload/files/pidaluvareb.pdfIn PDF document text
    • http://imhkayseri.com/resimler/files/nixidukasekojawed.pdfIn PDF document text
    • https://erinmillssmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/7iekge8honad8e4s0n52acvdf5/3664475453.pdfIn PDF document text
    • http://curry-box-deluxe.de/userfiles/file/kifapubid.pdfIn PDF document text
    • https://bangprice.com/bangprice.com/beta/cms_image/file/65640345960.pdfIn PDF document text
    • https://www.yoursurveysurveyors.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16128b68945344---jigopurujawolinodu.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/16136f08247e75---69835335617.pdfIn PDF document text
    • http://svaz-podnikani.cz/files/file/zokuxabot.pdfIn PDF document text
    • https://thewaves.net/wp-content/plugins/super-forms/uploads/php/files/n1ouvh5u5jg5vhl3jd5jiast4n/junawifozufurazomolupi.pdfIn PDF document text
    • http://vivalepurrexotics.com/clients/2/2f/2f65fe2011b8f0b07f64c29a74835a02/File/2999742739.pdfIn PDF document text
    • http://aranykoronakft.hu/userfiles/file/9881952230.pdfIn PDF document text
    • http://stlnsk.ru/uploads/file/87282497931.pdfIn PDF document text
    • https://bluetact.com/locktactyuma/userfiles/file/16055436327.pdfIn PDF document text
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16116dc6a78c7a---mepevofanopofosop.pdfIn PDF document text
    • http://fortlauderdalelimorental.net/wp-content/plugins/formcraft/file-upload/server/content/files/16086b7d93dc58---mezifexinuvaserur.pdfIn PDF document text
    • http://51www.org/uploadfile/file/9683d700b7bb83bb2929b817c08e681b.pdfIn PDF document text
    • http://www.deadclan.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160853381f3250---61653282046.pdfIn PDF document text
    • https://www.capitalroofingct.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6229b9b289---6329686563.pdfIn PDF document text
    • http://mobydick-band.de/fckdata/file/tewarag.pdfIn PDF document text
    • https://cargotavio.ru/files/file/dexejivavomu.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1f3619e866---rafosetoxepamevorajem.pdfIn PDF document text
    • https://edoxmarketing.com/wp-content/plugins/super-forms/uploads/php/files/i1jv9qn6gdn2mbb3mshl69kdh9/judalenalubalowupevam.pdfIn PDF document text
    • https://discoverapartmentsforrent.com/wp-content/plugins/super-forms/uploads/php/files/2d63aa1fa153875e879eb6b151c847d4/xirelimibapipibabu.pdfIn PDF document text
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1612d540725afa---kosapumesejamelerexoje.pdfIn PDF document text
    • http://studiomistretta.com/userfiles/files/10343344292.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=leveraged+loan+market+pdfPDF 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_off0000dfea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFEA 17056 bytes
SHA-256: e48759d2c3528c30d84e4501506ac245f50e5b7550051719b6455afbcd97550d
font_01_sfnt_off00010be2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BE2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000123f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123F9 10696 bytes
SHA-256: 9fde8ef6510a65d6461f0dd200b9356c0b63811b097b014c8420efdae118c4c8