Malicious PDF — malware analysis report

Static analysis result for SHA-256 7fdb025c85415b2b…

MALICIOUS

PDF

89.7 KB Created: 2021-08-20 02:06:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: d64994ee907c9f6f14c746a3a0766e6d SHA-1: 72b35e29f1484dc18ad481df2c70551c408645d2 SHA-256: 7fdb025c85415b2b01579cf3c886b1ee4252d3032432ab406017e0d5fab6223d
156 Risk Score

Malware Insights

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

The PDF was flagged by ML and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, pointing to numerous distinct hosts, many of which appear to be compromised WordPress upload directories. The document body is heavily obfuscated and unreadable, suggesting the primary function is to redirect users to external, potentially malicious, sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9884

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://tandprotheses.com/ckfinder/userfiles/files/24440220395.pdf In PDF document text
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/9fi7e894l25msl02ig34017iof/65529247293.pdfIn PDF document text
    • https://bestmiamiturf.com/wp-content/plugins/super-forms/uploads/php/files/912ec20cf8789b9b44ab9b7e3b293945/wesaloketetipugezi.pdfIn PDF document text
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/ec6slphfk8k2t023fookkj66le/sidasezitejusuriji.pdfIn PDF document text
    • https://qamarapps.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b11081c375d---52459296865.pdfIn PDF document text
    • http://dush-kz.ru/uploads/fck/file/fadegutabiker.pdfIn PDF document text
    • http://bascobrunswick.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608646dd0a754---xugevopo.pdfIn PDF document text
    • https://maidintown.co.uk/wp-content/plugins/super-forms/uploads/php/files/6b4aca2e940445b2f297e8b9b95ea8da/51706076594.pdfIn PDF document text
    • http://nhasachconggiao.com/luutru/files/54884063903.pdfIn PDF document text
    • http://xn--b1ahhafccpgkb2bxo.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/23600f5c053be1001db658d2f243acb7/78534934229.pdfIn PDF document text
    • https://magerp.org/upload/files/82809346431.pdfIn PDF document text
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2d9ab55023---63353940195.pdfIn PDF document text
    • https://aydin-elektrik.com/resimler/files/24785285721.pdfIn PDF document text
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/sq489643f82hocucr96l2k849m/vunoso.pdfIn PDF document text
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/160811573c8e8d---lisigezo.pdfIn PDF document text
    • http://plncse.hu/php_data/file/73222942287.pdfIn PDF document text
    • https://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073b95851339---11976191418.pdfIn PDF document text
    • http://ontheedgeofnow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160766deeb2a56---berumumo.pdfIn PDF document text
    • http://vejwun.cz/images/loruzuxiw.pdfIn PDF document text
    • http://thefutureofgolf.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1608c4b54ae065---73941659152.pdfIn PDF document text
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/nghh1e886jvv55c8lc1h5k8me3/26184084968.pdfIn PDF document text
    • https://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160ae245ba31c7---60881728027.pdfIn PDF document text
    • https://askopenko.com/wp-content/plugins/super-forms/uploads/php/files/2065bd827e6942c141bbbd849e63b033/20629402293.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/lndr4nsa6k21c74quh1kovar4e/wawapibegikup.pdfIn PDF document text
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/1609fa380efc77---bovonerijuwonibunaz.pdfIn PDF document text
    • https://hazeloyun.com/calisma2/files/uploads/97021013602.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=what+are+the+best+chips+to+cook+in+an+air+fryerPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f993.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF993 17144 bytes
SHA-256: 8b1dffa8dc6d56f373d86c3e1cf52fd26d5e9749f1f82e22efc99fd4a931b9c2
font_01_sfnt_off00012637.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12637 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013e4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13E4E 10872 bytes
SHA-256: 62ed3f3308f976ef6ef7593209421d59c56c956ea457a2fe8164aa84646d023d