Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b716020c4c099c1…

MALICIOUS

PDF

86.0 KB Created: 2021-09-19 01:47:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9e6a9b63b05f2d4da50fc05c4fc0068b SHA-1: 1b092eff8c49a2a4e3aa0cc25f154df34a79ab3f SHA-256: 3b716020c4c099c1220e02ad0c38ceb43d12dc145e04b3935425c18a84aef6ce
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress upload storage or disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of malicious redirection tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://ketchas.ru/uplcv?utm_term=best+multiplayer+games+for+android+with+voice+chat
    • http://gf-location.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613f344eba432---89602520395.pdf
    • http://ytovietnam.net/ckfinder/userfiles/files/femafunenosofokizadupezep.pdf
    • http://stroi-sistema.ru/img/43408375957.pdf
    • https://drhuanghair.com/uploads/files/202109150706273633.pdf
    • http://jsushibrea.com/uploads/files/72314643739.pdf
    • http://secureyun.cn/uploadfile/file///2021091215242570.pdf
    • http://balogmihaly.hu/UserFiles/file/jiwumer.pdf
    • https://www.auto-ecole-rive-droite.fr/ckfinder/userfiles/files/21740145537.pdf
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/ltq9updobjqrddi92getn40t06/renuzewakoso.pdf
    • http://ksnjl.com/userfiles/files/sabikiwoga.pdf
    • http://szjwwj.com/userfiles/file///44079357648.pdf
    • https://lazerom.pro/media/file/xetarili.pdf
    • http://obasekiestates.com/UserFiles/file/gadorabe.pdf
    • http://taxiluzern.ch/khurasan/userfiles/files/12225587568.pdf
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1613c4a732086e---22142482583.pdf
    • http://www.prieteniitehnicii.ro/documente/file/23781494033.pdf
    • https://kirbas.com/img/uploaded/file/zomubodeduv.pdf
    • http://sinice-rasy.cz/files/file/44988999523.pdf
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16133fa9731c58---91866653059.pdf
    • http://coconut.hu/userfiles/file/gozadezugazozewob.pdf
    • https://sledovani.gpshlidac.cz/www/userfiles/files/ruxisagewikidideseferugi.pdf
    • https://trompis-tondschungel.de/userfiles/file/bubuxoz.pdf
    • https://zhongzing.com/uploads/files/202109110932296420.pdf
    • http://vindindex.nl/images/uploads/namimezusinemeromunuduwet.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_off0000eb95.bin
c64d1695c0ec3e3d24c59ca954f5b7b0c54ec90d2f5b2062c62308bdbd291a97
pdf-font-stream PDF embedded font (sfnt) at offset 0xEB95 11484 bytes
font_01_sfnt_off00010679.bin
49ea063d36f96741dbcbf1ca5e5340bb3519c7acb8c9e2cbef5638aa78bfdfe4
pdf-font-stream PDF embedded font (sfnt) at offset 0x10679 16816 bytes
font_02_sfnt_off000131f8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x131F8 16792 bytes