Malicious PDF — malware analysis report

Static analysis result for SHA-256 679afe4c87a79b29…

MALICIOUS

PDF

69.8 KB Created: 2021-10-03 18:20:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: aadfa7f94e319a727e11f6afc64a90b2 SHA-1: 7adab03ad76aeaf5e755affa116d661dbe5a93a3 SHA-256: 679afe4c87a79b29e29f8079459606155f20c1f323e120d688553891092be811
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with numerous URLs pointing to compromised or disposable hosting. The document body is heavily obfuscated and unreadable, suggesting an attempt to hide its true purpose, which is likely to redirect users to malicious sites for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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 https://laborke.ru/uplcv?utm_term=a+shape+with+5+vertices PDF link annotation
    • http://tiszaladany.hu/upload/file/bujepiv.pdfIn PDF document text
    • https://ita.kru.ac.th/ckfinder/userfiles/files/95450864440.pdfIn PDF document text
    • http://andreuma.madteam.net/ckfinder/userfiles/files/kudepozexefejisi.pdfIn PDF document text
    • https://essuances.com/ckfinder/userfiles/files/tutuwi.pdfIn PDF document text
    • https://www.medicalbi.com/ckfinder/userfiles/files/9746060274.pdfIn PDF document text
    • http://bakefruit.com/uploads/files/202109022316456378.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614939cc5a00a---fenoz.pdfIn PDF document text
    • http://ruben.pl/ckfinder/userfiles/files/62906651215.pdfIn PDF document text
    • http://essentielles-theater.de/UserFiles/File/volofopoxuzewodubura.pdfIn PDF document text
    • http://www.azurwelcomeservices.com/userfiles/file/75759122830.pdfIn PDF document text
    • https://mosconi.net/userfiles/file/56767671146.pdfIn PDF document text
    • http://truhlarstvi-strakonice.cz/files/file/wuvomefekofaxusowixosabo.pdfIn PDF document text
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16158022a29f6b---6682586843.pdfIn PDF document text
    • http://beverly.kopanramen.com/uploads/files/nazid.pdfIn PDF document text
    • http://steffis-strassladen.de/userfiles/file/bukab.pdfIn PDF document text
    • http://tlw.ro/UserFiles/file/vuxivipenetil.pdfIn PDF document text
    • http://seasonsblinds.com/uploads/ckfinder/userfiles/files/80349832542.pdfIn PDF document text
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/161599bf0ed955---fovazibidarugurotede.pdfIn PDF document text
    • https://mimpishio2bet.com/contents/files/viluzepenonilerijofolura.pdfIn PDF document text
    • http://nktrading.qa/file/files/vuragiwaz.pdfIn PDF document text
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146b7e47b6aa---77267689826.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_off0000af56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF56 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c76d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC76D 10468 bytes
SHA-256: 657e40d493d7d65716824132cdc1f0d7b1fa4be3eec5a479333293e89ecef08b
font_02_sfnt_off0000df8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF8B 16440 bytes
SHA-256: 428532dba4afc0d2d963cbfd06b2d3b9d77b03dd1deed88b93d29707964e1fae