Malicious PDF — malware analysis report

Static analysis result for SHA-256 8582ac7659e6f300…

MALICIOUS

PDF

94.3 KB Created: 2021-09-18 13:01:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 48bf5fac4c45caec43d450d932586592 SHA-1: 52c701613a1c2dea63e5dd4a0612f4aa8f39b6b2 SHA-256: 8582ac7659e6f300f39fac3a4494e8767f4856c981b4b495e7ad69aaa9d95864
172 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The sample was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate the presence of embedded JavaScript and a link farm pointing to multiple external URLs, some hosted on compromised CMS uploads. The JavaScript likely serves to execute malicious actions or redirect the user, while the link farm aims to obscure the true destination and potentially host further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 8

  • 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.
  • JavaScript action low 1 related finding PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://colegiumaniucarei.ro/ckfinder/userfiles/files/metiwakelefiw.pdf In PDF document text
    • http://ekogamma.pl/javascript/ckfinder/userfiles/files/nujaralalonu.pdfIn PDF document text
    • http://findusafranchise.com/files/files/velasowusajijolapalajus.pdfIn PDF document text
    • http://offerparts.com/upload/files/57543560439.pdfIn PDF document text
    • http://blow-w124.com/js/upload/files/maganozafavax.pdfIn PDF document text
    • https://bucatariizidite.ro/printuri-fi/files/wavop.pdfIn PDF document text
    • https://living-stone.lu/userfiles/files/zivosufof.pdfIn PDF document text
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613418307ad68---xatujikodafijulafibepi.pdfIn PDF document text
    • http://bangtutrang.com/upload/files/27521742521.pdfIn PDF document text
    • http://oris-am.com/editor_up/towafinupivasup.pdfIn PDF document text
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/1613c39c18c77c---taroj.pdfIn PDF document text
    • http://xn--aknmedcal-wpbe.com/uploads/file/77288406857.pdfIn PDF document text
    • https://ensegun2.com/ckfinder/userfiles/files/bolofalukujada.pdfIn PDF document text
    • https://bindazzled.com.au/wp-content/plugins/super-forms/uploads/php/files/adc6960084a46ae08c1c3700ee8e7ee7/midumub.pdfIn PDF document text
    • http://henanshuangxin.com/d/files/47547387463.pdfIn PDF document text
    • http://chickenwild.com/upload/contents/images/images/80018119703.pdfIn PDF document text
    • http://kowalstwwo.pl/public/cms/images/file/70495896614.pdfIn PDF document text
    • http://klpa.net/userData/board/file/77899988687.pdfIn PDF document text
    • https://jodhpurtravels.com/nbloom/fckuploads/file/31496479127.pdfIn PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/kq3ieel46lgh31kotk8i5t7rui/95957302954.pdfIn PDF document text
    • https://avukatwebsitesi.kocgrafik.net/upload/files/69320290718.pdfIn PDF document text
    • https://www.partyshuttlebus.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16140d905e7370---zogutotixovetijuvupe.pdfIn PDF document text
    • http://topp.pl/_topp/file/dujopoxowobedusezosi.pdfIn PDF document text
    • https://xyoaa.org/sites/default/files/files/92079430559.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=mortal+kombat+sequel+moviePDF 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_off00010c71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C71 17832 bytes
SHA-256: bbec840405be25480425ff2d583d0792363bcb2129150ba4c53954334a040a53
font_01_sfnt_off00013aba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13ABA 10700 bytes
SHA-256: cc3172b4bf538c29e3f6fbdcaf51e8af547248bf285f0efd81cd9ace378701e7
font_02_sfnt_off00015360.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15360 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1