Malicious PDF — malware analysis report

Static analysis result for SHA-256 424e7fb9c890673d…

MALICIOUS

PDF

79.9 KB Created: 2021-09-05 15:43:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c621161a649ee0003b9d0a32b5d224e4 SHA-1: 78a09f541c146f506e738b212ee1ca0bc2e47a58 SHA-256: 424e7fb9c890673d7525c780498cf882bcda5d66749cefbddeec1e0a6bbf5524
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 a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for SEO poisoning or directing users to phishing sites. No scripts were extracted, and the document body was unreadable, but the heuristic firings are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://vytvarnyobchod.cz/UserFiles/File/85089139154.pdf
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dffa6be9e70---95287164560.pdf
    • http://asckhn.com/acskhn/userfiles/file/7028418291.pdf
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/1611c146f39aee---54620176382.pdf
    • https://krimgranit.ru/wp-content/plugins/super-forms/uploads/php/files/3e70acd9b9fba0db0c997827e5a6e519/94237631192.pdf
    • http://eatatrudy.com/uploads/files/53165695252.pdf
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/umdsmvrr4mal2u1vd227t74fa2/wugajexuwidizagezuxufivux.pdf
    • https://fleschimmo.lu/userfiles/files/16099236910.pdf
    • http://jjinline.org/file_upload/file/49289103877.pdf
    • https://manage3.realtourvision.com/rtv/ckfinder/userfiles/images/files/wesusefezugodoken.pdf
    • https://www.reliancecareuk.com/wp-content/plugins/super-forms/uploads/php/files/f44f08bef0df6522545a811e6c62a60f/6439882547.pdf
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/160a4ca3499f80---65806813655.pdf
    • http://bodymindspiritconnection.org/clients/5/53/53f1eac0d8ee32431a47b4e1af774f29/File/xaxigovova.pdf
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a335ac67099---wuwurituga.pdf
    • http://shmountaineering.co.uk/wp-content/plugins/super-forms/uploads/php/files/tljsbt7nt177mcne3i7nmciqa7/nosumajezazoge.pdf
    • http://tdvvietnam.vn/webroot/img/files/gipedafap.pdf
    • http://mim2010.ru/userfiles/file/69712577011.pdf
    • http://vstarmp.cn/upload/files/20210717_010221.pdf
    • http://lso-msm.fr/userfiles/file/linadafevogulapukejenebu.pdf
    • https://global-brand.net/userfiles/files/tikekusiratipemo.pdf
    • http://vakantie-noordlimburg.nl/ckfinder/userfiles/files/milanabezijimireta.pdf
    • http://naturestuff.nl/siteimages/file/vikinezitikajavas.pdf
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/f46ebca3d8aec6e2f92b2fb440e12f90/49691112169.pdf
    • http://tctrack.vn/images/newtech/files/8521222837.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=convert+pdf+to+kindle+ebook+format
    • 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_off0000d3d0.bin
a811cd7fc664458389d06f2d93fc6a752ab22b77516006b4c2bfec76557812fe
pdf-font-stream PDF embedded font (sfnt) at offset 0xD3D0 17492 bytes
font_01_sfnt_off00010111.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10111 16792 bytes
font_02_sfnt_off00011928.bin
0c39791d37f222bd74d5acdae328a05634fcd0b7093f29e7a70c75caaba0b568
pdf-font-stream PDF embedded font (sfnt) at offset 0x11928 10820 bytes