Malicious PDF — malware analysis report

Static analysis result for SHA-256 39b491c8d12fd5f0…

MALICIOUS

PDF

80.3 KB Created: 2021-09-05 21:25:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 88ecf8c358a21a2a40c5c22113d024bb SHA-1: eb505b0807ce4ba359139951a4ea5e9091910734 SHA-256: 39b491c8d12fd5f0a318498f113f13d8858c61de5ac031d30d28c9cb5ea24d2e
156 Risk Score

Malware Insights

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

The sample was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links pointing to compromised WordPress sites and other disposable hosting, indicating a link farm designed to redirect users. The PDF structure and embedded links suggest an attempt to exploit vulnerabilities or trick users into visiting malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://primax.fr/wp-content/plugins/super-forms/uploads/php/files/lkmg4hnfpkqa66tuoc6n4ffde3/35735704670.pdf In PDF document text
    • https://sambelteri.com/contents//files/jeguwagadinozagenu.pdfIn PDF document text
    • http://bobas24.pl/Upload/file/migotaguvotumetimupugetan.pdfIn PDF document text
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/7de9bf833070fca7a52f5929cba2fd84/35040252566.pdfIn PDF document text
    • https://jetzterstrecht.hamburg/wp-content/plugins/super-forms/uploads/php/files/uomhfheuu05km4nn5df8m8h337/nufibug.pdfIn PDF document text
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/1bdaf9be2b325f4d11643b543966f7f7/fegivex.pdfIn PDF document text
    • https://www.movingwithmagna.com/wp-content/plugins/super-forms/uploads/php/files/fa18bbadafbe9743bd6af99250014ce5/xerokinepezugisoko.pdfIn PDF document text
    • http://plusbateria.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8e0fca94da---tugofarilareja.pdfIn PDF document text
    • https://davebakeragency.com/wp-content/plugins/super-forms/uploads/php/files/f9755f54a94b36f435ace1a63236bb15/tapijewemuxawawuximepugof.pdfIn PDF document text
    • http://world-green-hope.com/uploads/files/14797768201.pdfIn PDF document text
    • http://gavinlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/13121556482.pdfIn PDF document text
    • http://bloomx.com/sites/all/sites/bloomx.com/files/kijit.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/3fjgkeakoidsuh36uvu6aaf0o2/18099749127.pdfIn PDF document text
    • http://dbhsreunion.com/clients/21010/File/nawobufavuviwulivin.pdfIn PDF document text
    • http://bachova-terapia.sk/images/file/38195181794.pdfIn PDF document text
    • http://soflacops.com/clients/83266/File/pigafojevotevabez.pdfIn PDF document text
    • http://www.cddfct.com/up_files/file/273278192.pdfIn PDF document text
    • https://ltgtrends.com/wp-content/plugins/super-forms/uploads/php/files/c9bb8354d3a7b2842148d2a53fca5025/57271286418.pdfIn PDF document text
    • https://perfecthospital.org/FCKeditor/file/jijagolurekegujepe.pdfIn PDF document text
    • https://accuratesearch.com/userfiles/file/niboderitir.pdfIn PDF document text
    • http://tetobox-budapest.hu/uploads/files/turerebopazudilotupabi.pdfIn PDF document text
    • http://80tner.netsociality.com/upload/files/tezovevo.pdfIn PDF document text
    • http://shrlie.com/upload_fck/file/2021-9-1/20210901165509955186.pdfIn PDF document text
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/bdbc8d62bcd1373d280236802a816eea/turifidujativo.pdfIn PDF document text
    • https://moniimpex.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba059e639eb---87587824714.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=simple+present+tense+exercise+with+answer+pdfPDF 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_off0000cfb6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFB6 19304 bytes
SHA-256: ff3d6f3da680c9e99daaec81395dd0f89d0e839c50012547c490adafa4ed0278
font_01_sfnt_off00010182.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10182 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011999.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11999 11028 bytes
SHA-256: 1d41abb010988d40daaa2d2784048424e58484e2516b7bca0d031ad43c179cf0