Malicious PDF — malware analysis report

Static analysis result for SHA-256 552101bc60fa3d63…

MALICIOUS

PDF

85.8 KB Created: 2021-08-31 23:26:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 87cac7a540bae64be17160d6f5ef6e23 SHA-1: d4516038d4bd664e18e23867b5b9e98c7c377073 SHA-256: 552101bc60fa3d63c159d79055696bf35d8006ea81dc104f04cc4265a7b365e3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous URLs pointing to compromised WordPress sites and disposable domains. The embedded URLs and link farm structure suggest an intent to lure users to malicious sites for phishing or further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://vanillasky-ch.com/images/files/56950989276.pdf In PDF document text
    • http://solyaris.pro/admin/ckfinder/userfiles/files/97243886165.pdfIn PDF document text
    • http://print-resource.co.uk/ckfinder/userfiles/files/88737483122.pdfIn PDF document text
    • https://discoverapartmentsforrent.com/wp-content/plugins/super-forms/uploads/php/files/e33c3f12a24e4b32f0239cb1a674014e/80559708889.pdfIn PDF document text
    • http://plenar.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160b115a9d2453---rudetira.pdfIn PDF document text
    • http://robalton.es/Albums/images/file///96976822945.pdfIn PDF document text
    • http://trendybiz.in/usersfiles/file/teradidazofijatig.pdfIn PDF document text
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160adc669af363---11152497527.pdfIn PDF document text
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/160f90a87ca4a3---93810506041.pdfIn PDF document text
    • https://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160a1f8bb8db90---jijeguxifitimi.pdfIn PDF document text
    • https://advik.net/userfiles/file/44605467504.pdfIn PDF document text
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1607731371cb72---89523842502.pdfIn PDF document text
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac089d9fcf4---nebumerujemeg.pdfIn PDF document text
    • http://www.melloecastro.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fa912820d4---814974794.pdfIn PDF document text
    • http://www.prieteniitehnicii.ro/documente/file/85527453766.pdfIn PDF document text
    • https://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16107da0527792---nitosovibofisuwe.pdfIn PDF document text
    • https://www.sidertest.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609d410a4220d---kidefirojefigupunuxudu.pdfIn PDF document text
    • https://nicemexico.net/wp-content/plugins/formcraft/file-upload/server/content/files/16081cc02c4c68---butolukakokimelapasizeguf.pdfIn PDF document text
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/8n7c1h5v31tfguj4os7826j3q6/divojukixufajut.pdfIn PDF document text
    • http://dekoblickfang.de/userfiles/file/kexodasovetupekufamadosag.pdfIn PDF document text
    • http://clarklawtexas.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/55049432050.pdfIn PDF document text
    • https://www.medicalart.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160d1ae3dbc4f8---23542712920.pdfIn PDF document text
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/li6hstvdao5cti6ncfp9t9per8/jobibuk.pdfIn PDF document text
    • https://flylights.pl/wp-content/plugins/super-forms/uploads/php/files/1idv5md61afik1kens986l90ja/felanobixivatotizap.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=how+do+you+say+frog+in+spanishPDF 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_off0000e5ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5BA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fdd1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDD1 10792 bytes
SHA-256: 1739bf0a27f5c123f9ff40e9d238a80a3612c1f486f9d190bd52bbc5e9c628a8
font_02_sfnt_off0001165a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1165A 19336 bytes
SHA-256: 0f03806285aef2b68dbc9f06c79d6d427dcdc8c0fadbe0b552e41bf1be418fb6