Malicious PDF — malware analysis report

Static analysis result for SHA-256 431a0b94cdc9c1b8…

MALICIOUS

PDF

79.2 KB Created: 2021-09-24 03:28:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 8cc7c640627ab9bcf4736a023cf81a8c SHA-1: 9ab98448308f12c3d3f5db482dbf5142c8150e8e SHA-256: 431a0b94cdc9c1b84e789429bf22dee678fbe5c78c0f2b3a6540f715d4876d53
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, so the primary attack vector appears to be the embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 6

  • 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.
  • 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://krisoc.ru/uplcv?utm_term=what+does+smurf PDF link annotation
    • https://cam-ceeds.org/ckfinder/userfiles/files/24974622245.pdfIn PDF document text
    • http://fecirturizm.com/resimler/files/tipijuboma.pdfIn PDF document text
    • https://candica.pl/ckfinder/userfiles/files/kinidogajuruxeme.pdfIn PDF document text
    • http://patrick-jardinage.fr/ckfinder/userfiles/files/56128680022.pdfIn PDF document text
    • https://royal-art.pl/uploads/userfiles/files/kikatukajaxigurulebawip.pdfIn PDF document text
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/161484ade494ce---xemorofamujog.pdfIn PDF document text
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1612f7c7ccd622---77574005399.pdfIn PDF document text
    • https://sailstudy.in/ckfinder/userfiles/files/koxuxesepaluxuwawepi.pdfIn PDF document text
    • https://walkandsmile.com/userfiles/file/88318589309.pdfIn PDF document text
    • http://donovaly-ubytovanie-safran.sk/web/userfiles/file/xeliso.pdfIn PDF document text
    • http://www.mousumibanerjee.com/fckimages/file/modupozepuxizamejuwusuv.pdfIn PDF document text
    • http://jjkxmy.com/upload/files/202109111934462801.pdfIn PDF document text
    • https://pmfegypt.com/userfiles/files/bizanukerijajebovim.pdfIn PDF document text
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b056113e1e---puxutogaterujuru.pdfIn PDF document text
    • http://inggeo.eu/userfiles/files/nujafofa.pdfIn PDF document text
    • https://kokomanis.com/contents/files/52508444206.pdfIn PDF document text
    • http://trainternational.in/wp-content/plugins/formcraft/file-upload/server/content/files/1613e7179ea672---34139945077.pdfIn PDF document text
    • https://stw-nowogard.pl/download/file/57610514690.pdfIn PDF document text
    • https://habrit.tw/ckfinder/userfiles/files/18179661545.pdfIn PDF document text
    • https://inprovituruguay.com/ckfinder/userfiles/files/narubewanogepa.pdfIn PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/6cv6q7lkudiolvvmqovsnafbei/diromevamutaronob.pdfIn PDF document text
    • http://grafosaleservice.cz/images/fck_editor/file/57161448192.pdfIn PDF document text
    • https://alley.52886.tw/uploads/files/66472226352.pdfIn PDF document text
    • http://robedecreateur.com/img/files/renipojifukozidujimi.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_off0000d1f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1F7 10472 bytes
SHA-256: db3ae14823d80014b05f3c57b211facefaaaef9eb712bb2adb7b93522c4b2dd7
font_01_sfnt_off0000e9c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9C7 17664 bytes
SHA-256: 3de00140613eb5165eee0b5d0e36f2218016eb3d17915cf0cb705f6184d3b2c6
font_02_sfnt_off0001179f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1179F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1