Malicious PDF — malware analysis report

Static analysis result for SHA-256 23c81fb0ed24ee55…

MALICIOUS

PDF

84.0 KB Created: 2021-07-17 08:58:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 13c8f4766b8d595edcf06a4ae54014b1 SHA-1: 047145c564e0624c5f1a3c94c3bd72a4a3ab9a67 SHA-256: 23c81fb0ed24ee554e94c204b88603417d417dc67a43f9ddc659ad8e09194554
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple compromised WordPress upload directories and disposable hosting sites. These links likely serve as a distribution point for further malicious content or phishing attempts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://iweldbot.com/ckfinder/pho/files/welajuxeg.pdf In PDF document text
    • https://independentmusicleague.com/wp-content/plugins/super-forms/uploads/php/files/8c1ffd5f1a54a4d51c86b9278f3c77e7/zogisuta.pdfIn PDF document text
    • https://www.pension-chevaux-haras-gabereau.fr/ckfinder/userfiles/files/xafike.pdfIn PDF document text
    • http://studiosaletta.it/userfiles/files/faburimenovezot.pdfIn PDF document text
    • http://ed-web.cz/userfilesfile/17752101333.pdfIn PDF document text
    • https://rffsev.ru/wp-content/plugins/super-forms/uploads/php/files/ab3b4895940f4dd1137fe8f23a26c756/41433435896.pdfIn PDF document text
    • http://anhuifan.com/upload_fck/file/2021-6-1/20210601141141590342.pdfIn PDF document text
    • http://ihdbd.org/upload/files/22619953102.pdfIn PDF document text
    • https://michaels-limo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c4579daee19---69067238816.pdfIn PDF document text
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1608db91decca5---48077186665.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/e40447921dd75dd3d4bd1efa85ab65eb/72267909638.pdfIn PDF document text
    • https://simovi.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160c94f11c3feb---91310382883.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/nubodanujo.pdfIn PDF document text
    • http://clair-environnement.eu/catalogue_dynamique/file/70297854361.pdfIn PDF document text
    • https://hmjrgoldhockey.org/wp-content/plugins/super-forms/uploads/php/files/f2938b312c893af58ae8247069fc8756/72433117788.pdfIn PDF document text
    • http://dalnoboy.org/data/filestorage/upload/files/pimafefatudokutak.pdfIn PDF document text
    • http://eshop-kocicinadeje.cz/files/file/86502118695.pdfIn PDF document text
    • https://www.sidertest.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c3d8daf0653---84565080257.pdfIn PDF document text
    • http://www.rkcomdesignservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608848722ed61---15205602338.pdfIn PDF document text
    • http://www.asejnrtigers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a9b5fcbcebf---wanewinikafabivefuwag.pdfIn PDF document text
    • http://ranagro.com/files/vigipufulefuvorafejevun.pdfIn PDF document text
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/pjm1no5fi15098a56rdku3lsha/19303337151.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/160902a14da9f1---29035866912.pdfIn PDF document text
    • https://renebeumer.nl/userfiles/file/52901644350.pdfIn PDF document text
    • http://pvsystexperts.com/wp-content/plugins/super-forms/uploads/php/files/d73ka8kdv4skchpcd152l4q6f0/bowesefozafiwuxapuwu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=blocked+number+iphonePDF 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_off0000e641.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE641 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fe58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE58 10736 bytes
SHA-256: 48ec5b2fbc3d4b693df6cfa8701821a01c47298a706e9831ee5e333eb4522fdb
font_02_sfnt_off00011675.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11675 16940 bytes
SHA-256: f0b08cfd41f2896326201c5408440612b2a8025438cdeef1b8d4627dba371d38