Malicious PDF — malware analysis report

Static analysis result for SHA-256 37f9960f94dd2b50…

MALICIOUS

PDF

82.2 KB Created: 2021-09-19 05:26:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: d8a1f73c4af40d4760d0328050a14c2b SHA-1: 4184dd131c2520df790c1b47137db8f94d517539 SHA-256: 37f9960f94dd2b50f20586fe10c163d0f8d1ff226c516bd4fccb32cb334b0025
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, indicating a link farm designed for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports the conclusion that this PDF is part of a campaign to direct users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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://pistant.ru/uplcv?utm_term=photo+to+pdf+converter+app+for+android PDF link annotation
    • https://www.info-service.com.tw/plugin/ckeditor/ckfinder/userfiles/files/saxeko.pdfIn PDF document text
    • https://fminterativa.net/cms/plugins/ckfinder/userfiles/files/sukepevas.pdfIn PDF document text
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/161329bad76e20---93818611548.pdfIn PDF document text
    • http://sancheonglittletheaters.com/upload/userfiles/2021/09/files/210907095620.pdfIn PDF document text
    • https://songhong-thudo.com/img/files/6388953486.pdfIn PDF document text
    • https://pmms-online.com/assets/file/48936286634.pdfIn PDF document text
    • https://systematix.pl/userfiles/file/sajalasenitexejewozuku.pdfIn PDF document text
    • https://maria-galland.ru/files/file/4117255871.pdfIn PDF document text
    • http://www.argentum.com/wp-content/plugins/super-forms/uploads/php/files/6lopfst7vovv9ehsetv8ouu212/lowitatuwuxinif.pdfIn PDF document text
    • http://apothepharma.com/upload/files/xolunawivijezuvezufolirav.pdfIn PDF document text
    • http://lakesnwoodskerala.com/uploads/file/95209347891.pdfIn PDF document text
    • http://monticellotownship.org/userfiles/file/sadurebejelejef.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161379f5a1ae2d---22691981273.pdfIn PDF document text
    • http://mq-water.net/upload/lobidigojapewafibusilunab.pdfIn PDF document text
    • http://fratellibeninca.com/images/file/83084393095.pdfIn PDF document text
    • http://bagiez.de/userfiles/file/loguxivud.pdfIn PDF document text
    • http://kleni.cz/userfiles/file/27096566158.pdfIn PDF document text
    • http://dkkarsin.pl/img/upload/files/43261917792.pdfIn PDF document text
    • https://sunarchegypt.com/userfiles/file/bajajadiji.pdfIn PDF document text
    • https://safetypadlocks.eu/eurostyl/photos/file/10365870830.pdfIn PDF document text
    • http://herve-coiffure.ci/files/lalukejivunanatutenaxeg.pdfIn PDF document text
    • http://redigonda.it/userfiles/files/91302089922.pdfIn PDF document text
    • http://maslatalaia.com/userfiles/file/napisuxa.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/161425ec9ad891---duwesa.pdfIn PDF document text
    • http://magicfood-cn.com/files/20210916131537.pdfIn PDF document text
    • http://antichigelsi.it/userfiles/files/9567182436.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_off0000dd96.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD96 10572 bytes
SHA-256: aea51aeecd1c3b74051707bff980cb1d4cc1c8df6bdf2cdebff92ed8eb283551
font_01_sfnt_off0000f5af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5AF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010dc1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DC1 17484 bytes
SHA-256: 4ca74a2e86191d4680d6b45884582fa3fdbdc8001a408be46aaf2e364431611d