Malicious PDF — malware analysis report

Static analysis result for SHA-256 21535ab6fc5de474…

MALICIOUS

PDF

83.4 KB Created: 2021-09-01 18:03:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 54e7684fbe2d64b26b37675d6654b3c7 SHA-1: 802a01dfccefcfb70cae4f391c98f2d949483f52 SHA-256: 21535ab6fc5de4742fea496463d3ea5b5e9b6f3e3d868160bcb7d7396dced803
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF contains embedded JavaScript, which is often used to redirect users to malicious sites or download further payloads. The PDF also contains a link farm pointing to compromised WordPress upload storage, indicating a phishing or redirection attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9983

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://kiavysocina.cz/UserFiles/File/75968741882.pdf
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/c796b0e1dbbd354501e9c57bf5e63913/kenofufopakafosej.pdf
    • http://azbuka-d.ru/ckfinder/userfiles/files/65629799504.pdf
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16087f957dd0f8---45920660333.pdf
    • https://www.spitalmoldovanoua.ro/ckfinder/userfiles/files/9356974716.pdf
    • http://pospatrans.cz/UserFiles/File/kavifujotupexewafiwe.pdf
    • http://dcbestwings.com/uploads/files/xezafazadafi.pdf
    • http://mcutech.net/files/89051174335.pdf
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e9a5c8ed79---muvowebadumekav.pdf
    • https://psiakocky-potisk.cz/webpagebuilder/ckfinder/userfiles/files/tiwagudenifalal.pdf
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612c05235fe01---lasitumutufafobasa.pdf
    • http://phenix-security.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16073e04241582---47525708714.pdf
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a5743c4caf1---tepajaveresurodifinabeje.pdf
    • https://pcetravel.com/files/file/26018381166.pdf
    • http://sparan-art.ru/ckfinder/userfiles/files/mosojewirilafo.pdf
    • http://morgancountyoh.com/userimages/mededaxopereralan.pdf
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e1d14458a2d---32594541715.pdf
    • https://baodinhsolar.com/wp-content/plugins/super-forms/uploads/php/files/js7bt74nmr36ae116m4hi2qub6/61443984700.pdf
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ebc5fd9bd0---guxalekudugolomofenimewi.pdf
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d8ddf921a44---3581619864.pdf
    • http://divorce-difficile.fr/userfiles/file/7308613215.pdf
    • https://bykevin.com/wp-content/plugins/super-forms/uploads/php/files/5315345f2195495691803784971d26ac/3537989462.pdf
    • https://konferencii.ru/js/ckfinder/userfiles/files/siziragopozaxa.pdf
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b957236eb1---pimewevatefugeselokev.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=how+to+use+a+manual+light+meter
    • 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_off0000e275.bin
12be45bc720264f742b9547a5e6f62496e319630dd72d772568d2253552b9d9d
pdf-font-stream PDF embedded font (sfnt) at offset 0xE275 17176 bytes
font_01_sfnt_off00010ea3.bin
3a20ceae570b2bdb4a8c690129c32d81276a3bc2d9113963e131c4827a77f482
pdf-font-stream PDF embedded font (sfnt) at offset 0x10EA3 10732 bytes
font_02_sfnt_off00012718.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12718 16792 bytes