Malicious PDF — malware analysis report

Static analysis result for SHA-256 c1d8550825139274…

MALICIOUS

PDF

93.1 KB Created: 2021-08-06 18:04:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 075aeb61e1a64d6734f2e806a2961530 SHA-1: 38ad090a0de60e45b58d9d4ce9b9a1dcdff3d7d1 SHA-256: c1d8550825139274a8193979a5cc46b36f219230b01f4054a13e6d9df208c5e5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a link farm directing to multiple websites, with several hosted on compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for SEO manipulation or phishing. No scripts were extracted, and the document body was unreadable, limiting further analysis of specific payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9876

Heuristics 6

  • 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.
  • 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://verypool.cn/images/upload/File/somusobavelizidok.pdf In PDF document text
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1607df60dcd318---91469562835.pdfIn PDF document text
    • https://www.msolartop.cz/wp-content/plugins/formcraft/file-upload/server/content/files/16079606873529---87588166504.pdfIn PDF document text
    • https://www.indee-r.fr/wp-content/plugins/super-forms/uploads/php/files/4db45c2d7ffb8cf0941b0d71649fe72e/riwoxajulopovurupekufava.pdfIn PDF document text
    • http://openendrep.com/userfiles/files/wolojunobaw.pdfIn PDF document text
    • http://galettedesrois.hu/userfiles/file/gumuzu.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b8346da339c---13531027999.pdfIn PDF document text
    • http://zzps.pl/userfiles/file/71981074925.pdfIn PDF document text
    • http://vejwun.cz/images/waxuletibijut.pdfIn PDF document text
    • http://www.peopleoftheheath.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d4b9fdae333---432088533.pdfIn PDF document text
    • http://3e-machinery.ru/app/webroot/filesfiles/30014633615.pdfIn PDF document text
    • https://kildevangen.dk/files/dafelizesoguzojolelisuw.pdfIn PDF document text
    • https://atasuorganiktarim.com/upload/ckfinder/files/ludutukamavefoviruro.pdfIn PDF document text
    • http://omg50yrs.com/clients/6/6d/6dc66c997efb3e4e8ce6e6e7d0694e91/File/zufijanabu.pdfIn PDF document text
    • http://www.biogreeno.com/cms/ckfinder/userfiles/files/vuniruduresi.pdfIn PDF document text
    • http://chono.mn/uploads/userfiles/files/tanopiwajumivifu.pdfIn PDF document text
    • http://www.finanzanlagen-honorarberatung.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c94367b7c48---semigimubukekije.pdfIn PDF document text
    • http://netinflux.net/userfiles/file/83986567035.pdfIn PDF document text
    • http://kuhomania.ru/ckfinder/userfiles/files/80515240546.pdfIn PDF document text
    • http://fredericjean.net/oplusco/file/48554755284.pdfIn PDF document text
    • http://associatedreclaimed.com/userfiles/files/33038855663.pdfIn PDF document text
    • http://www.sec-ollivier-associes.fr/www/upload/file/13175128570.pdfIn PDF document text
    • https://oneremote.ru/wp-content/plugins/super-forms/uploads/php/files/fbeb20e55cffe7231ffe1f73ef7a3ab9/63430504735.pdfIn PDF document text
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a97a6ce407---19564122477.pdfIn PDF document text
    • http://nuovojob.com/userfiles/files/filof.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/pfni8eo9888n3pv6fgm2mrom01/nupexuvedinixim.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=atem+television+studio+pro+hd+resetPDF 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_off000103cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103CB 10640 bytes
SHA-256: 979c53acc557cf9efb5adf05ff40bee413e042cdc8ead1da662310af80a1bcd2
font_01_sfnt_off00011beb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BEB 19232 bytes
SHA-256: 868b1cdbe17d05aa8dee45d009c47efb86bc0511e4e0d75129f351f645c4a812
font_02_sfnt_off00014d1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14D1C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1