Malicious PDF — malware analysis report

Static analysis result for SHA-256 af3de4f828930a8a…

MALICIOUS

PDF

80.8 KB Created: 2021-09-05 11:59:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 18913b49047d35b3c6749f8ecef047e3 SHA-1: f68f071ceb381c6977b5ce9b8b9e9a703792d378 SHA-256: af3de4f828930a8a7ced2ab7339b8abae114c3214859bdc4dee6ba6eae0bb57b
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress sites, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent, with the URLs likely serving as the primary attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://smidgel.ru/uplcv?utm_term=abrir+pdf+sin+descargar+android PDF link annotation
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160819e109fbb1---sedofizoragosa.pdfIn PDF document text
    • http://coffee33.ru/archive/file/fibinito.pdfIn PDF document text
    • https://www.habitat-morvan.fr/ckfinder/userfiles/files/luwinowuvefidokigi.pdfIn PDF document text
    • http://whalesart.com/uploadfile/file///2021052210374041.pdfIn PDF document text
    • http://autowagon.it/userfiles/files/vosipavekigep.pdfIn PDF document text
    • https://frontiersneurophotonics.org/wp-content/plugins/formcraft/file-upload/server/content/files/1/160a540febfecc---wejureta.pdfIn PDF document text
    • https://monacollection.ua/wp-content/plugins/super-forms/uploads/php/files/70386d977786c8177534d960f0ecfc53/23053746757.pdfIn PDF document text
    • https://singaporeroadshow.com/wp-content/plugins/super-forms/uploads/php/files/cba4a7494202edbfc58df90f2671b034/53744704392.pdfIn PDF document text
    • https://ketex.com/trcgp/ckfinder/userfiles/files/sakebevexole.pdfIn PDF document text
    • https://syntellect.ru/Repository/file/16949601310.pdfIn PDF document text
    • http://lowry-averyreunion.com/clients/c/c0/c0e4e7922159a76f956c19110b7bfeb7/File/wasavez.pdfIn PDF document text
    • http://cycling-software.com/files/file/58486658937.pdfIn PDF document text
    • https://www.antoniopopolizio.it/ckfinder/userfiles/files/sobuvowetoxadota.pdfIn PDF document text
    • https://hpx.com.ua/wp-content/plugins/super-forms/uploads/php/files/0768170018f4b4775da7b17dffc95905/22282842092.pdfIn PDF document text
    • http://short-story.ru/upload/file/sujatufisamolum.pdfIn PDF document text
    • http://highlevel.pl/userfiles/file/xovurowavomut.pdfIn PDF document text
    • https://nepalonetours.com/userfiles/files/bifiwipo.pdfIn PDF document text
    • http://www.biosafety.biz/ckfinder/userfiles/files/mademim.pdfIn PDF document text
    • https://greenways.at/userfiles/file/wijejumejaboju.pdfIn PDF document text
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bca7f21c7c9---zekuviviji.pdfIn PDF document text
    • https://irepairplus.nl/app/webroot/files/userfiles/files/toxugorufitidat.pdfIn PDF document text
    • http://schubert-hh.de/image/file/falozagadiso.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_off0000d836.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD836 10772 bytes
SHA-256: 4d77e6c50af19cd08b942b371a68cd62b48aaa719dadd3d47f632d4f5743744d
font_01_sfnt_off0000f0ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0AD 17516 bytes
SHA-256: 8b98b8c4c1d67ae6ac0d4fdca8844e693e004b9b5bfe4e59f85cbdbee28d4ca5
font_02_sfnt_off00011d1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D1C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1