Malicious PDF — malware analysis report

Static analysis result for SHA-256 31d9abba10ef2feb…

MALICIOUS

PDF

87.7 KB Created: 2021-07-25 18:50:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5c4e4e38cc3174e43e5eff0bcbe65c75 SHA-1: a141513385d2f96855111fe45db6d5b778ee099e SHA-256: 31d9abba10ef2febaa73603bfa88ffdbfb36d24b9d65f1617f5189467b84dfb5
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to compromised CMS uploads and disposable hosting, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery via these links. No scripts were extracted, and the document body was unreadable.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://kythuatviet.vn/uploads/userfiles/file/labitoti.pdf
    • http://naasschoolofmotoring.ie/fckeditor/userfiles/file/nukizokivasav.pdf
    • https://www.axelendinggroup.com/wp-content/plugins/super-forms/uploads/php/files/fb798677690809f068f5f7885c178833/barajabiremafemelo.pdf
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc0e573c4a---rasalesajurobulajadu.pdf
    • https://triosms.com/userfiles/file/zefipox.pdf
    • http://anandtouristcorporation.com/uploads/fasakipuvumasuxijaziruja.pdf
    • https://fietenhaardenenkachels.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a05e1de8dbb---14338379315.pdf
    • http://stylist.in.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1609f274d41086---mesug.pdf
    • http://nwatchonline.net/userfiles/file/86564989753.pdf
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/160a2f3ae1f9b8---77929056527.pdf
    • https://alakharia.com/public_html/userfiles/file/zupebapasexo.pdf
    • http://xn--80aafkqcanfpgnhbng3b5i9a.xn--p1ai/pict/file/32479396776.pdf
    • https://ski-experience-japan.com/images/blog//file/35189233573.pdf
    • http://bmcnx.com/userfiles/file/65857958880.pdf
    • http://www.asejnrtigers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160bca17a1a690---jepoma.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089b25d8513e---83369638501.pdf
    • https://varbackaforskola.se/ckfinder/userfiles/files/fuvosezil.pdf
    • http://okna-dvere-online.cz/media/upload/upload/file/somowake.pdf
    • http://mariopresto.pl/userfiles/file/41540984289.pdf
    • https://www.hsbofmn.com/ckfinder/userfiles/files/kanumaxovodevazojomud.pdf
    • http://entone.es/wp-content/plugins/super-forms/uploads/php/files/a438847eccfb44f9449317e96d8e28be/45137837922.pdf
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dc141914dea---lojetafoloziwuroxipelivak.pdf
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c51ddab98b1---wizaniwat.pdf
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/h5iiok6skgnrasj0qvegm7c637/55231889934.pdf
    • https://xn----7sbabak5acz7byau.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/27bcb1bab11134360a72d6b6e9a871e6/89290849688.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=how+to+fix+throttle+pedal+position+sensor
    • 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_off0000f40d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF40D 16792 bytes
font_01_sfnt_off00010c24.bin
390398bf072167eb74ccce08afb6d48196517ec77b0946c14137769ba4373c56
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C24 10776 bytes
font_02_sfnt_off000124e2.bin
c899c5428579f1f74013323001fb778f5eb960185444cb09bafb218370048744
pdf-font-stream PDF embedded font (sfnt) at offset 0x124E2 16848 bytes