Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8ba3675d0a2108f…

MALICIOUS

PDF

68.1 KB Created: 2021-09-26 21:17:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5545aeab7daa67224bb1b6fee8a8a4e5 SHA-1: d7198e211555e041edb6f75783c5a67da0d4a269 SHA-256: c8ba3675d0a2108f7b43217afd9f2503d5ed1b0ebe5a81fd0b379a76f7427a7f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised WordPress sites and disposable hosting, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, but the PDF structure itself is used to facilitate the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://cructi.ru/uplcv?utm_term=spanish+word+that+starts+with+p
    • https://auf.vn/wp-content/plugins/super-forms/uploads/php/files/mura0f80nevndg7ice4dcj42c7/23554982660.pdf
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c813243cf4---babadoj.pdf
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/16136cb8c0e70d---74711423340.pdf
    • https://anne-berger.de/sites/anne-berger.de/files/fkcfile/xexufuxitabelosam.pdf
    • http://refpecsbelvaros.hu/kepek/files/mepigisilatunigodapagik.pdf
    • http://paradisetourkorea.com/FileData/ckfinder/files/20210917_4120285EC7B14299.pdf
    • https://thietbixanh.net/uploads/files/repigojilubugekeki.pdf
    • https://acatay.daynexdemo.tk/upload/ckfinder/files/25898274438.pdf
    • https://ifacemount.com/wp-content/plugins/super-forms/uploads/php/files/18sj63ka2kfailkrdo7cqj0lk2/bubaxowelelopupelapovobod.pdf
    • http://3suntech.com/UploadFile/file/20210914110138356.pdf
    • http://toyotarent.hk/FileData/ckfinder/files/20210906_B154E0960BA353E7.pdf
    • https://best-turbos.com/wp-content/plugins/super-forms/uploads/php/files/d8a8652e4cf833b6304be2b97c35abf7/20283886805.pdf
    • https://www.supremecaravans.com.au/application/third_party/ckfinder/userfiles/files/xavewexufezobi.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614629aa79452---25325810098.pdf
    • https://nepalihemp.com/ckfinder/userfiles/files/24483301062.pdf
    • https://5ky13lu3-1251.com/contents/files/kokijibutakuxufo.pdf
    • https://terminal.hr/userfiles/file/buwebixedasawesubivopum.pdf
    • http://chaukitchen.com/uploads/files/kaset.pdf
    • http://canoeing.by/pics/files/6540932440.pdf
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/0ee1b7f51fcf5e6166a926430e4e27a0/70008143166.pdf
    • http://nofatrans-int.com/userfiles/file/5370828964.pdf
    • 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_off0000ad8f.bin
ad1462dadc8003425e549a0f556cc7e584e932ad0197b1ebb40dfced4278c030
pdf-font-stream PDF embedded font (sfnt) at offset 0xAD8F 10472 bytes
font_01_sfnt_off0000c554.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC554 16792 bytes
font_02_sfnt_off0000dd66.bin
cad73b4602b8f72c31e69435b85374d9932baee4ca5206d6e909a04cf42aa4ce
pdf-font-stream PDF embedded font (sfnt) at offset 0xDD66 14956 bytes