Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f42cd81dc80f285…

MALICIOUS

PDF

77.3 KB Created: 2021-09-08 22:51:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: d6c2ca57911b542d146ab7ba99e83ed0 SHA-1: 5e113583ff81ec6920118e21620f280db57f6ab1 SHA-256: 8f42cd81dc80f285e2f1a289cc6097b09879667d9ec10af553548c7686114615
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which are hosted on compromised or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. The embedded JavaScript is likely used to facilitate the redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://nomylo.ru/uplcv?utm_term=how+to+get+into+my+android+locked+phone PDF link annotation
    • http://bladensburg.abwingsmd.com/uploads/files/40361020642.pdfIn PDF document text
    • https://paidionresearch.com/userfiles/files/81364085715.pdfIn PDF document text
    • http://ceresasrl.it/userfiles/files/9200752366.pdfIn PDF document text
    • http://ambvetesopo.eu/userfiles/files/47218734561.pdfIn PDF document text
    • https://www.drserapkagan.com/wp-content/plugins/super-forms/uploads/php/files/8kgn0rgqbnfjmo027t7n9s3hu6/59280747465.pdfIn PDF document text
    • http://perechen-izdaniy.ru/js/ckfinder/userfiles/files/16653068671.pdfIn PDF document text
    • http://proxima-design.cz/files/file/jozetox.pdfIn PDF document text
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ed5a3b3953---34416652728.pdfIn PDF document text
    • http://debsecond.net/UserFiles/File/rolovax.pdfIn PDF document text
    • http://americandeliorder.com/uploads/files/32127759232.pdfIn PDF document text
    • https://bahceneryaman.net/public/content-images/files/36418219289.pdfIn PDF document text
    • http://tdsns.ru/userfiles/file/zirefuxurakej.pdfIn PDF document text
    • http://vladekoservis.ru/files/mazekaxururesewovajeledif.pdfIn PDF document text
    • http://colegiosantarosa.com/uploads/imagem/file/xupusijov.pdfIn PDF document text
    • https://maconlux.lu/userfiles/files/vomesivapolofa.pdfIn PDF document text
    • http://nawaress.com/webroot/js/ckfinder/userfiles/files/72179592141.pdfIn PDF document text
    • http://gat-asset.com/CKEdit/upload/files/wadobezesazonebuzumaga.pdfIn PDF document text
    • http://bandbaajabarat.com/ci/userfiles/files/16722119018.pdfIn PDF document text
    • http://dellalontra.it/userfiles/files/dojazifuvot.pdfIn PDF document text
    • https://gamletaarnhuset.no/wp-content/plugins/formcraft/file-upload/server/content/files/16137d90a83f76---49832680901.pdfIn PDF document text
    • https://goez3.com/10005001208290177/ckfinder/userfiles/files/pesabelebolofifel.pdfIn PDF document text
    • https://newegys.egyseg.eu/ckfinder/userfiles/files/71173018308.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/16134d8ad3432f---584177036.pdfIn PDF document text
    • https://mgc.to/sites/web/upload/files/73252483885.pdfIn PDF document text
    • https://www.marbelitesa.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1612ec5f02462e---soniriwugofipefo.pdfIn PDF document text
    • https://www.oasipizza.it/wp-content/plugins/formcraft/file-upload/server/content/files/16133a5d77eb06---27521839197.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_off0000c912.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC912 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e129.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE129 11076 bytes
SHA-256: 6b511b5ecc6eef0216ccfa32f32fd9cab7e85048e0e8bd37989802dd2601bd0d
font_02_sfnt_off0000fa90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA90 17328 bytes
SHA-256: 9d953b515d5b8df2c359d75a0c0725e39fa457772c7246e188477c7f66b89c26