Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1f7f17d73edc4e4…

MALICIOUS

PDF

84.2 KB Created: 2021-07-09 07:01:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 81903d2777acb6cd93ee875778add584 SHA-1: 694effb1931affbae6ca571a4dca099b47ad7657 SHA-256: a1f7f17d73edc4e475962a5c1ac5ffd33a18fed2f01c74aaddd66ede71fd317c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as a malicious PDF by ClamAV and an ML classifier. It contains numerous links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users. The presence of external URI heuristics and link farm indicators strongly suggests the PDF's purpose is to lead users to malicious external content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://4bx.pl/public/file/zukewowajudabut.pdf
    • http://azizolace.cz/images/file/85900337600.pdf
    • https://premiumtrade.ro/ckfinder/userfiles/files/47325088279.pdf
    • https://csom.cz/wp-content/plugins/super-forms/uploads/php/files/052da862fa1fc73616ff4cf8cafe1445/xajatavetikusogikis.pdf
    • https://chefinhogourmet.com/wp-content/plugins/super-forms/uploads/php/files/69bf5c126fd78b393149dcae525e8abf/lodanefukazukifugozije.pdf
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/160713b3b7edc6---92733279138.pdf
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bf31eb0ecc---45412462524.pdf
    • http://noahsmarinesurveyors.ca/userfiles/file/88343381969.pdf
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/16077c7bded9f7---51833513120.pdf
    • https://fanaf.com/article_ressources/file/ruxuzaxefatil.pdf
    • http://bjsprt.com/uploadfile/file///2021053004214827.pdf
    • https://paron-rebondir.com/uploads/files/16285428698.pdf
    • http://blankheich.de/images/uploads/file/gotitemiditukunipotafovu.pdf
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/96239757408.pdf
    • https://mrmobilewebsite.agency/wp-content/plugins/super-forms/uploads/php/files/718d74d853fa9b449accdb65b4cd6479/karududuboj.pdf
    • https://comesa.com.pe/wp-content/plugins/super-forms/uploads/php/files/95cv3nb88j99kf9doh9t6odmh2/23168642504.pdf
    • https://www.proctoloji.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074d98186d65---97858245113.pdf
    • http://softwarefactory.nl/images/file/vivobolafuvabamemese.pdf
    • https://takiminsahada.com/wp-content/plugins/super-forms/uploads/php/files/hl0tv5opmk68d5c2ojhf3pbh2k/wezogigili.pdf
    • http://udokutscher.de/gfx/userfiles/files/gonovuvugito.pdf
    • http://www.rkcomdesignservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160719560f177b---8660476988.pdf
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609d85286de68---munetozuziw.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=mcqs+on+chemical+kinetics+with+answers
    • 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_off0000e239.bin
37e2ae3493808785ff15dc79cd5e19d08e4e8929c065c1ac2506afaac67c67fd
pdf-font-stream PDF embedded font (sfnt) at offset 0xE239 18124 bytes
font_01_sfnt_off000112a1.bin
d01630695b93226dfd48500ef4b1c1c2b84effd9788108ae36ae796fe833c0e2
pdf-font-stream PDF embedded font (sfnt) at offset 0x112A1 10812 bytes
font_02_sfnt_off00012b6f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12B6F 16792 bytes