Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1d7af13bda5c448…

MALICIOUS

PDF

85.8 KB Created: 2021-09-08 23:52:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 3820abe60e13820d5316e6c3196122c5 SHA-1: 18076ee38892309ef6421c3c3ac6f74690856df4 SHA-256: b1d7af13bda5c44874b2b526784970bc0118be1c8fbd2151e2753df1a81b9908
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as a phishing trojan. It contains embedded JavaScript, which is a common technique for executing malicious code within PDFs. The file also includes numerous links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious or phishing content. The ML classifier also strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://www.casestilistas.es/ckfinder/userfiles/files/defimunik.pdf In PDF document text
    • http://timnhanhonline.net/upload/files/5894021189.pdfIn PDF document text
    • http://rosesrealtyhomes.com/userfiles/files/pesepeworuverarodufiduse.pdfIn PDF document text
    • https://www.hs-hofgastein.salzburg.at/ckfinder/userfiles/files/80050140593.pdfIn PDF document text
    • http://katyababash.com/images/uploads/file/33293405982.pdfIn PDF document text
    • http://gianphoiduyloimodel.com/Images_upload/files/72086714439.pdfIn PDF document text
    • http://www.css-jp.com/upfile/files/2021/09/02/zegitusixilajaxovoguroniw.pdfIn PDF document text
    • https://christianboudreau.com/wp-content/plugins/formcraft/file-upload/server/content/files/161373822129f3---22117505576.pdfIn PDF document text
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/161353ae921b81---6090493400.pdfIn PDF document text
    • https://transdeliveris.lt/userfiles/file/nasejelijoroduli.pdfIn PDF document text
    • https://weblative.com/wp-content/plugins/super-forms/uploads/php/files/rss6gt18c8b0nruoht41pcg44g/15984726667.pdfIn PDF document text
    • http://belgium-ex.com/images/blog/file/fapetesaze.pdfIn PDF document text
    • http://snieznik.pl/userfiles/file/2169010594.pdfIn PDF document text
    • http://vattucongtrinh.com/userfiles/file/99112010146.pdfIn PDF document text
    • https://speedwayinfo.hu/uploads/file/sagoxifenevezazafixada.pdfIn PDF document text
    • https://vas-vill.hu/userfiles/file/tapifatijebijanido.pdfIn PDF document text
    • https://irish-setter-zucht.info/ckfinder/userfiles/files/judopikediruna.pdfIn PDF document text
    • http://ana-jsc.com/upload/files/94491005071.pdfIn PDF document text
    • http://cetis156.neutronds.com/assets/js/ckfinder/userfiles/files/nikerojubavoj.pdfIn PDF document text
    • https://ost-fogging.com/upload/files/4436576359.pdfIn PDF document text
    • https://leanuslab.com/UserFiles/file/57574918415.pdfIn PDF document text
    • http://tydafa.com/dafa/uploadfiles/20210902193531.pdfIn PDF document text
    • http://thsport.dk/ckfinder/userfiles/files/guburad.pdfIn PDF document text
    • https://skinrepublic.vn/webroot/img/files/notopukezefiposobozuwaxod.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=speed+up+android+phone+2019PDF 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_off0000ea5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA5A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001026c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1026C 17620 bytes
SHA-256: fd64887c4dd7edc294517acdc876f18d34117a50bcbafcfb3a53159de91787cb
font_02_sfnt_off00013085.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13085 10812 bytes
SHA-256: 17609b03a256ba9b05fc48e318e61a4479ac83f180cf49ec7a63eb685ee93498