Malicious PDF — malware analysis report

Static analysis result for SHA-256 2b84a393b97b9330…

MALICIOUS

PDF

81.7 KB Created: 2021-09-05 22:35:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: e6c4ee5ce6517a273e63f5b60d96109f SHA-1: 3c289888ec15ad04432a3dcdc73db3dfb4a56290 SHA-256: 2b84a393b97b9330012ccdccb5ac0dde640e78224ce4afe3ce2a5caa3f767acd
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites and other domains, suggesting a phishing or malware distribution scheme. The presence of external URI heuristics and link farm indicators further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://krisoc.ru/uplcv?utm_term=manualidades+con+botellas+de+cristal+recicladas PDF link annotation
    • http://www.everhouse.lt/wp-content/plugins/formcraft/file-upload/server/content/files/1608499a34c2f8---wanagudulelumas.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160bc536d36f76---tinimoferaxepelaxo.pdfIn PDF document text
    • https://www.le-domaine-de-hauterive.fr/ckfinder/userfiles/files/nubiguwifumitekazit.pdfIn PDF document text
    • http://kavtas.com/images_upload/files/276586296.pdfIn PDF document text
    • http://liburnia.pl/userfiles/file/90529672268.pdfIn PDF document text
    • http://studiomilano.eu/userfiles/files/vezamanafob.pdfIn PDF document text
    • https://europeancustomtailor.com/wp-content/plugins/super-forms/uploads/php/files/c2edf96fcf3076b4ccee2939fd2afdb1/panezuvo.pdfIn PDF document text
    • https://www.hungryalex.com/wp-content/plugins/super-forms/uploads/php/files/a5f98f59f49553ca50c7a7c79f1bc90e/putunorivexomorofurez.pdfIn PDF document text
    • http://walkandwagforveterans.com/clients/9/96/96cc06f6b2a5429c1325f0b535cddba6/File/67905431272.pdfIn PDF document text
    • http://giaydantuongphongkhach.net/images/news/file/nijalajeganamiw.pdfIn PDF document text
    • https://www.westcountrystoves.co.uk/wp-content/plugins/super-forms/uploads/php/files/dafd79b6200ceae06b738fec01809eb5/wasujulavilefuxaxixi.pdfIn PDF document text
    • https://raptiherbal.com/ckfinder/userfiles/files/bagekaxajabatigimakax.pdfIn PDF document text
    • http://mdbim.pl/ubezpiecz/obrazy/file/mugorunitovekiruvatukij.pdfIn PDF document text
    • https://www.urban-quartz.co.uk/wp-content/plugins/super-forms/uploads/php/files/22f297117196af4a9fa71336052a7da0/6221238670.pdfIn PDF document text
    • https://menu2uplus.com/images/file/73301073574.pdfIn PDF document text
    • http://aquarium-kochi.com/app/webroot/ckfinder/userfiles/files/zixumepuxajanasuguz.pdfIn PDF document text
    • https://sbsoftware.ro/admin/userfiles/file/93591267377.pdfIn PDF document text
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/vi1ht30890lj0s73obqq9ord5t/93455941671.pdfIn PDF document text
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075d5e478c62---77846696383.pdfIn PDF document text
    • http://studiotecnicodavico.eu/userfiles/files/vololowifi.pdfIn PDF document text
    • https://socialacademy.gr/wp-content/plugins/super-forms/uploads/php/files/a7ef9f5cf481d485ad0faba3f9580c1f/63861747800.pdfIn PDF document text
    • http://donauwell.at/userfiles/file/16943997780.pdfIn PDF document text
    • http://www.prctech-th.com/ckfinder/userfiles/files/79543822437.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_off0000d96c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD96C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f183.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF183 10596 bytes
SHA-256: c48ecf664d0eaf29940c23e50227b000ae47435642ad12ae792fafdf9aa951dc
font_02_sfnt_off000109ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109CA 17876 bytes
SHA-256: d46ee365a2e413cdbbcf84b86391844b5b905377a2ea66fcda23276959f68194