Malicious PDF — malware analysis report

Static analysis result for SHA-256 159ba61e1a5b8c66…

MALICIOUS

PDF

94.9 KB Created: 2021-08-15 02:52:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-17
MD5: 0b825a8aae7f386f10924362cab0e7d3 SHA-1: 993d8af155aaabcc5c4e8169fbfc55e66b185aa0 SHA-256: 159ba61e1a5b8c66055c5ff135d9d58f34ca87883125c346a0d7408d6f449ad0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to compromised WordPress sites and disposable hosting, suggesting a link farm or phishing lure. The presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this, indicating the PDF's primary function is to redirect users to potentially harmful external content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://infrive.ru/uplcv?utm_term=voltage+drop+calculations+excel PDF link annotation
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609e560f35fb1---nopifatixujibisege.pdfIn PDF document text
    • https://alexandrapanayotou.com/web/images/static/file/30365154568.pdfIn PDF document text
    • https://digireg.gr/upload/19611573407.pdfIn PDF document text
    • http://wojno-stal.pl/pliki/file/pejigoxefixiveligozavovod.pdfIn PDF document text
    • http://www.highlandmetals.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160afbac70b68d---tilof.pdfIn PDF document text
    • http://wadsoda.com/UserFiles/File/nefivefumaled.pdfIn PDF document text
    • http://industrialdevices.in/uploads/fovakevuwivikuse.pdfIn PDF document text
    • https://ddriu.hu/wp-content/plugins/super-forms/uploads/php/files/aea2c558a3f81b18f87df58ac8859fd3/60926755207.pdfIn PDF document text
    • http://www.orhancoskun.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608023d071e03---lilemilukevapegopukomulu.pdfIn PDF document text
    • http://www.blackhillsdancecentre.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8c443bde8b---90585957307.pdfIn PDF document text
    • https://arab-hams.com/Ups/files/99498704340.pdfIn PDF document text
    • https://sssmri.com/ckfinder/userfiles/files/95241229888.pdfIn PDF document text
    • https://psystat.net/candyticket/uploads/page_images/files/rewumive.pdfIn PDF document text
    • http://jshtextile.com/UserFiles/file///bobitofukevasonavoviwuw.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/tmdvb40de1696msmh19kmsv5j5/16638819733.pdfIn PDF document text
    • http://garderoba.sk/images/_file/veluvafufifexokowinuw.pdfIn PDF document text
    • http://hosungtour.net/FileData/ckfinder/files/20210726_B8249D812C43AFA9.pdfIn PDF document text
    • https://em.heephong.org/ethnicminorities/cmsadmin/ckfinder/files/83765274521.pdfIn PDF document text
    • http://www.c-l-r-p.com/admin/ckfinder/userfiles/files/66897850480.pdfIn PDF document text
    • https://bgmediation-flm.com/userfiles/file/43934480212.pdfIn PDF document text
    • http://jiangsutravel.kr/userfiles/files/20210815_080313.pdfIn PDF document text
    • http://csc0451.com/userfiles/file/20210719123342_mp8z4w.pdfIn PDF document text
    • http://www.teeintact.com/admin/fckeditor/editor/filemanager/connectors/php/img/file/70074146948.pdfIn PDF document text
    • 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_off00010107.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10107 23752 bytes
SHA-256: 3a51b86ab526ac1b05593a9f470dd7a1930dce7385acec132a16a2681c250345
font_01_sfnt_off00013ccd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13CCD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000154e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x154E4 10860 bytes
SHA-256: d70d947402447ee3892e86c5f4b8db12840041e475fe742f6e6ca3603fd99ad5