Malicious PDF — malware analysis report

Static analysis result for SHA-256 f79d3c8fe31ef23a…

MALICIOUS

PDF

128.8 KB Created: 2021-07-23 12:43:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3d7405826d2c7250606144ac6bd92e30 SHA-1: bc7e77568fc22146e46ddcedac86ec391917aeff SHA-256: f79d3c8fe31ef23a7d37f17bbc8cfe39ec1cfad0eda7200ee5c72d4f6e0d5f2a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to distribute traffic. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, and the document body was unreadable, limiting further analysis of the specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9802

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://coffee33.ru/archive/file/vimidurisudadijukirar.pdf
    • http://maketmaster.ru/admin/ckfinder/userfiles/files/zituxatojokozefivojifajev.pdf
    • http://palyavalaszto.hu/teszt/upload/file/tudilusulinedusemozotu.pdf
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/16092828e8f5e8---29005416475.pdf
    • http://xn--o39a91gvwm83kbsn.net/FileData/ckfinder/files/20210613_82BA16C761F04398.pdf
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/160afbe85eea71---2037914611.pdf
    • https://vernadoc.com/wp-content/plugins/super-forms/uploads/php/files/a157a9025cff074f30e3364a1096ec4a/tujowasobigubaka.pdf
    • http://stellamaris.cz/userfiles/21894846691.pdf
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/160b4b4b5dec52---tosalenoxarofugokorafa.pdf
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7324a1da52---34284646858.pdf
    • http://moveisgarciadigital.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160942c73f08a8---famowefafolariwes.pdf
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/67evc37u1duo5aqan43pfin067/nuvuv.pdf
    • https://www.msolartop.cz/wp-content/plugins/formcraft/file-upload/server/content/files/160713c42bbdb8---tubupur.pdf
    • https://webtraffic.ch/wp-content/plugins/super-forms/uploads/php/files/k0k14qg1574cq7gm1nht3k8nfs/wovorogelapurisegemel.pdf
    • https://ontime-taxi.kg/wp-content/plugins/super-forms/uploads/php/files/f619a4bb9542756d86430c9714f05728/welazotolesoj.pdf
    • https://airbays.com/userfiles/file/46667209424.pdf
    • http://montgomery71.com/clients/34132/File/36811751706.pdf
    • http://brilliantsolarpaneling.com/userfiles/file/sopapaladuxukapiwij.pdf
    • http://askort.pl/Upload/file/73862377451.pdf
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b3c4e62038---saximowavejajo.pdf
    • https://www.taxikladis.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160aeaefc69057---38555098229.pdf
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160c5b8298636d---81950280463.pdf
    • http://baovephuongtroi.com/vietkiendo/upload/file/7933230047.pdf
    • https://digireg.at/upload/96316283664.pdf
    • http://cdseoulps.com/uploadfile/fckeditor/file/2409384050.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=indus+river+flows+through+which+states
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00016976.bin
0e691d4476720460be566c1e597694c9e121d756d6f31c065e8c84986ce82bc8
pdf-font-stream PDF embedded font (sfnt) at offset 0x16976 19856 bytes
font_01_sfnt_off00019d31.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x19D31 16792 bytes
font_02_sfnt_off0001b548.bin
b02421717ec8d84cdf450632c028e01929e5efaef2ec2ed741644dae66ed0a38
pdf-font-stream PDF embedded font (sfnt) at offset 0x1B548 10960 bytes
font_03_sfnt_off0001ce7a.bin
f1cee51f0a4b9c7623d5b931f15fb663bd922dad3a75cac680fe7bc9949a4ed4
pdf-font-stream PDF embedded font (sfnt) at offset 0x1CE7A 1948 bytes
font_04_sfnt_off0001d777.bin
5c51f444bf16702ca22405fb4d00cecc01f7febf0d8f0d29ba27fa3910643845
pdf-font-stream PDF embedded font (sfnt) at offset 0x1D777 18308 bytes