Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4b3745663b2497e…

MALICIOUS

PDF

70.1 KB Created: 2021-09-27 11:11:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 780b2eeeff5a4ca336315e49a59d3864 SHA-1: 12b0d664a1fd860b5d9f548933fb82333d69f8e3 SHA-256: c4b3745663b2497ea51e61b8cc0c557e6d6f8dcebf82f1328fce6a7f4da76a76
164 Risk Score

Malware Insights

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

The sample is a PDF containing embedded JavaScript, which is a common technique for exploiting vulnerabilities or redirecting users. The PDF also contains numerous external URIs, many of which point to compromised CMS upload storage or are part of a link farm on disposable hosting, indicating a phishing or malware distribution attempt. The ClamAV detection and ML classifier strongly suggest malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

Heuristics 7

  • 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.
  • 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 http://rungrawin-itt.com/userfiles/files/lusap.pdf In PDF document text
    • https://studiovizia.com/webroot/img/content/files/9973152646.pdfIn PDF document text
    • http://motoren-adachi.com/js/upload/files/71376642312.pdfIn PDF document text
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/1613269a10611a---88817814088.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/1614ebc1ba0168---84317596438.pdfIn PDF document text
    • http://chromavials.com/d/files/luzorekaxa.pdfIn PDF document text
    • http://www.ciesol.es/ckfinder/userfiles/files/84207037422.pdfIn PDF document text
    • http://bollnas.boj.se/uploads/userfiles/files/bomuwupabuwud.pdfIn PDF document text
    • https://whiteplacard.com/UserFiles/file/30791766861.pdfIn PDF document text
    • http://maychaybocaocap.com/app/webroot/uploads/files/26018930306.pdfIn PDF document text
    • http://fueandhair.com/userfiles/files/wodesaz.pdfIn PDF document text
    • https://myshalewell.com/userfiles/file/munovup.pdfIn PDF document text
    • http://nbc.com.vn/ckfinder/userfiles/files/25263205851.pdfIn PDF document text
    • http://honeycontacts.com/uploades/userfiles/file/jetanekexiriduluwuwexal.pdfIn PDF document text
    • http://kubabus.cz/novy-web/upload/file/75547257009.pdfIn PDF document text
    • http://wksx.top/images/userfiles/file/jeturukamatukumuja.pdfIn PDF document text
    • http://barahi.com/assets/userfiles/files/vekemigafiwaterujalotol.pdfIn PDF document text
    • http://mpwlawpa.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/59980167921.pdfIn PDF document text
    • http://beijingteye.com/upload/files/goxag.pdfIn PDF document text
    • http://fasson.vip/images/editor/files/kariwevuguxululo.pdfIn PDF document text
    • https://10playsolutions.com/clients/softklk/documents/_articles_/file/29372231836.pdfIn PDF document text
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614e8d66ce6df---19387175952.pdfIn PDF document text
    • http://heyumpnd.com/userfiles/file///koruboruzoz.pdfIn PDF document text
    • https://menu2uplus.com/images/file/mumumuwu.pdfIn PDF document text
    • http://www.verneteco.com/ckfinder/userfiles/files/lodupobuziwifejajid.pdfIn PDF document text
    • https://acryl-bg.com/userfiles/file/62599735033.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=watch+private+instagram+storiesPDF 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_off0000b4be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB4BE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ccd0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCD0 14532 bytes
SHA-256: 096845ea0245d7ef04d550e2491f5a2b14c7cff980030b7fb0f225a5e7c31ad5
font_02_sfnt_off0000f146.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF146 10832 bytes
SHA-256: b2f5214c638f453e3f06edd4753e9fc8d04be788d79267cc61a5505d63be0094