Malicious PDF — malware analysis report

Static analysis result for SHA-256 6735f6d7a3d87dc0…

MALICIOUS

PDF

87.5 KB Created: 2021-07-05 06:24:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 085138fa5b0078cbc986614d3a13752e SHA-1: 278363fc588b9207a55ae8c636b472580873861b SHA-256: 6735f6d7a3d87dc0f625eb512891bd4f7d5058b5c8a026fc937f611de714f2d8
164 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains embedded JavaScript, which is often used to execute malicious actions within PDFs. The presence of a link farm pointing to multiple distinct hosts, some of which appear to be compromised CMS uploads, suggests an attempt to obscure the final destination and evade detection. The primary goal appears to be redirecting users to external resources, likely for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://abugfreemind.com/userfiles/file/78913539999.pdf
    • http://www.alexgis.com/siteuploads/editorimg/file/kofegagotudubisedu.pdf
    • http://foire-fromages-et-vins.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072b32a749f5---4900535807.pdf
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e366e7c2d7---tirolukuz.pdf
    • http://dbcasagayathottam.org/assets/uploads/cms_images/files/44268614541.pdf
    • https://koetec.com/home/~ptow/public_html/ckfinder/userfiles/files/ziwuref.pdf
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/160aa69de6415e---tojivuvitigajikojiwaw.pdf
    • http://sl-light.ru/design/img/upload/file/litebavajipezutowa.pdf
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/160727b0cb986b---mirijixeba.pdf
    • https://dtcprojects.com.au/wp-content/plugins/super-forms/uploads/php/files/pshgpbmkhuu5519beucv09ti4p/67121645348.pdf
    • https://zazilha.com.mx/wp-content/plugins/super-forms/uploads/php/files/d372dff83cea9362622cfb26d3c8c569/25223295663.pdf
    • http://oguzlarotomatiksanziman.com/depo/sayfaresim/file/navavotidexejo.pdf
    • https://wlao.on.ca/wp-content/plugins/super-forms/uploads/php/files/e35938be2e0289d2c4f3159229dafb65/ziripopasu.pdf
    • https://eprobatdz.com/ckfinder/userfiles/files/31005337901.pdf
    • https://greshamgilessalon.com/wp-content/plugins/super-forms/uploads/php/files/4427cdf5d21bbe1bff148af888ec9093/98932462518.pdf
    • http://webdulich.com/js/ckfinder/userfiles/files/90025946532.pdf
    • https://gservicepz.com/wp-content/plugins/super-forms/uploads/php/files/0a1d1e3dac75522cd4398637c9755691/belew.pdf
    • http://daiichilogistics.com/uploads/news_file/degow.pdf
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/160964a806ff40---numinub.pdf
    • http://www.highlandmetals.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16078e497d804d---kodubasuzev.pdf
    • https://www.grandeprairie.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607905d54a9cb---50833775461.pdf
    • http://www.rebranded.tv/wp-content/plugins/formcraft/file-upload/server/content/files/160a243a1a94a7---jepufolefolopusadexo.pdf
    • http://clinicaveterinariagoitese.it/userfiles/files/difudubiputuxepavitu.pdf
    • http://kyanite.tv/userfiles/file/24332131333.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=workmate+400+owners+manual
    • 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_off0000f07d.bin
c4215d5782a8df44082c1f759224ca6f7b764f87fc2c3a5aa84a3ef8eee221c9
pdf-font-stream PDF embedded font (sfnt) at offset 0xF07D 18108 bytes
font_01_sfnt_off00012065.bin
36138a85326666eb9e2efb46ad654f291ecc6a92a114a5c62ff987685132579f
pdf-font-stream PDF embedded font (sfnt) at offset 0x12065 10648 bytes
font_02_sfnt_off000138ed.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x138ED 16792 bytes