Malicious PDF — malware analysis report

Static analysis result for SHA-256 31373f89b8c1c389…

MALICIOUS

PDF

86.9 KB Created: 2021-09-12 21:44:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 1241f633524ffbf75db6570c66771495 SHA-1: 9f00b94b0d9ae9d242e88b1c0afdca06a3297987 SHA-256: 31373f89b8c1c389196ee4f5ce228968aa13f86c765b051dbdfcceed6f3b4c3b
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs pointing to potentially compromised websites, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is unreadable, but the presence of multiple external URIs and a link farm heuristic points to a redirection-based attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://telegid.tv/userfiles/files/karivix.pdf In PDF document text
    • https://gastriklandsbf.se/UserFiles/files/69092579100.pdfIn PDF document text
    • http://sinsg.com/files/fckeditor/file/zerafuvi.pdfIn PDF document text
    • http://evevoyance.fr/adh/.-/file/gevupuxakijimar.pdfIn PDF document text
    • https://drainscovers.com/wp-content/plugins/super-forms/uploads/php/files/2ebb7fd6c36e010e57475ca5d3977929/71121050109.pdfIn PDF document text
    • https://dodatnojamstvo.com/userfiles/file/13348058506.pdfIn PDF document text
    • http://calisnt.com/uploads/files/19728485182.pdfIn PDF document text
    • http://maginsaatmetal.com/resimlerfiles/93043080637.pdfIn PDF document text
    • http://anhuizhkj.com/upload_fck/file/2021-9-9/20210909025434180307.pdfIn PDF document text
    • https://inprovitcaribe.com/ckfinder/userfiles/files/kolaw.pdfIn PDF document text
    • http://mikomisushi.com/uploads/files/77196814512.pdfIn PDF document text
    • http://hueide.com/upload/files/99303023703.pdfIn PDF document text
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/gg03gv3g2a12pqnj0qe2c30uup/zozupogowavafuxor.pdfIn PDF document text
    • https://vidaleve.ind.br/ckfinder/userfiles/files/50781262624.pdfIn PDF document text
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/ernsi0gd7t4p8mv7s7ulbsktka/99124728308.pdfIn PDF document text
    • https://truonggiangcompany.com/userfiles/file/31385156191.pdfIn PDF document text
    • http://ladyqueen.it/userfiles/files/nowewefurej.pdfIn PDF document text
    • https://bouveau-consulting.com/userfiles/file/65828305257.pdfIn PDF document text
    • http://beamstraffic.ae/amb/userfiles/file/14184597621.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/665d9f7da89a35ed3b99c23dfdfd9aa3/muzowudodinozubufurajidek.pdfIn PDF document text
    • https://haruhonpo.com/upload/haruhonpo/files/sizivavejadomipi.pdfIn PDF document text
    • https://tahitotfalu.hu/ckfinder/userfiles/files/56056205960.pdfIn PDF document text
    • https://venus-forever.com/image/files/86102897604.pdfIn PDF document text
    • http://kkslavicin.cz/sites/default/files/file/44037878263.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=xmen+first+class+online+freePDF 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_off0000ef27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF27 10504 bytes
SHA-256: ccc3af8baf688aa48b1a1d16531fed416ce2e9a84038a3baada0e227e89b6c23
font_01_sfnt_off00010704.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10704 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011f16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F16 18092 bytes
SHA-256: 74d11f27f0ae9233e427a547d0b81375d88d0623ebd7318954ad833a837f4e91