Malicious PDF — malware analysis report

Static analysis result for SHA-256 906cba3f76242d7c…

MALICIOUS

PDF

72.9 KB Created: 2021-09-26 07:52:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: aa4d90427bf3ce5c9decb9315f6de844 SHA-1: 4893be83b510a23dc23984b7ddc6bbeba0a1b34a SHA-256: 906cba3f76242d7cb3235a5dbcfa50488772e91a144987ec88d336cc0c7e6a12
156 Risk Score

Malware Insights

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

The PDF file contains a link farm with numerous URLs pointing to other PDF files hosted on various domains. Several heuristics indicate these domains are either compromised CMS uploads or disposable hosting, suggesting a deliberate attempt to obscure the final destination or host malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

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://davidhammerstein.org/ckfinder/userfiles/files/78441767850.pdf
    • http://guss-ex.de/uploads/fck/file/getamifezimaso.pdf
    • http://tropo-design.com/ckfinder/userfiles/files/wotugorazadidasejozamuke.pdf
    • http://aftckwt.com/uploads/file/fuvirikozenuwijegazo.pdf
    • https://www.hotelrestaurantmacarena.fr/ckfinder/userfiles/files/20732796410.pdf
    • https://formapolis.it/wp-content/plugins/super-forms/uploads/php/files/83cc3b27109129d9e8cd903a9c6d6987/lanevibini.pdf
    • https://martas.vodrsport.cz/uploads/files/zojezuxovifi.pdf
    • http://unibox.lv/files/text/fidapijibonene.pdf
    • http://cheers-gifts.com/userfiles/saviguvikapakoza.pdf
    • https://nedimgame.com/calisma2/files/uploads/sozokerasa.pdf
    • http://msslink.ru/userfiles/files/simotutepapu.pdf
    • http://studiolegaletrotta.eu/userfiles/files/turatuwotu.pdf
    • https://damsindia.org/admin/uploads/file/xirasutugepudusafebo.pdf
    • https://eownauto.com/uploadpic/files/sezirosonakozifa.pdf
    • http://prplus4u.com/ckupload/files/58410479062.pdf
    • http://neodentpetrosino.it/userfiles/files/17546298078.pdf
    • http://oreoltour.ru/sites/default/files/file/tadozumavite.pdf
    • http://ganan10.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/16131b6ff0a814---16296701715.pdf
    • http://daiichigroup.net/uploads/news_file/xunidakezitopa.pdf
    • http://culvercity.ilovepokebar.com/uploads/files/xekigegumolukazowo.pdf
    • http://global-gypsum.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141a7503c44a---levuselubenowazowe.pdf
    • http://fullcolorspandoeken.nl/userfiles/file/nozuruzufubegufubixas.pdf
    • https://ietc-oman.saktoon.com/userfiles/files/nanebosifatininogapuzif.pdf
    • https://razredna-nastava.net/files/tawik.pdf
    • https://slotpt2.com/contents/files/xejomuvofigogevimoji.pdf
    • http://bhk-aindling.com/userfiles/files/ridijomufefizaxewedawaf.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=unity+android+device+not+found
    • 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_off0000b5b5.bin
3535d309660bf4212c786d58b2f056c1c985f77cb296f25c2b52a9447ba89267
pdf-font-stream PDF embedded font (sfnt) at offset 0xB5B5 10544 bytes
font_01_sfnt_off0000cde5.bin
062ec542a91b5abd2861980ee85541d700036cd6c1e3e702ee81b91479d1dcb0
pdf-font-stream PDF embedded font (sfnt) at offset 0xCDE5 18176 bytes
font_02_sfnt_off0000fc92.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFC92 16792 bytes