Malicious PDF — malware analysis report

Static analysis result for SHA-256 11d8337ff0ac6e79…

MALICIOUS

PDF

81.7 KB Created: 2021-09-15 09:44:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 13c338556cb7e4c5fb0995a27557f22d SHA-1: 93e1d9d0d83f388fe792a3d2ad46f4277beb1d31 SHA-256: 11d8337ff0ac6e79836e5dafd8d7443ce875ab70417c46e5774e77a7f02d9282
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and an ML classifier as malicious, with ClamAV identifying it as 'Pdf.Phishing.Trojan'. The file contains numerous external links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' indicates a sophisticated attempt to obscure the final malicious destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 https://crewmak.ru/uplcv?utm_term=bedste+kamera+app+til+android PDF link annotation
    • https://coverline.ro/userfiles/file/87465979697.pdfIn PDF document text
    • http://aallergy.friend-match.com/upload/files/32617438801.pdfIn PDF document text
    • https://patoman.ro/ckfinder/userfiles/files/84604276375.pdfIn PDF document text
    • http://balletpanov.com/uploads/files/96295590912.pdfIn PDF document text
    • https://www.totalblissbeauty.com.au/application/third_party/ckfinder/userfiles/files/vuxisojigufaf.pdfIn PDF document text
    • https://uleshuzatabc.hu/files/file/9289909199.pdfIn PDF document text
    • http://meetburgerusa.com/uploads/files/76653657571.pdfIn PDF document text
    • https://rivieresoceanie.com/ckfinder/userfiles/files/99268789581.pdfIn PDF document text
    • http://dtmaso.com/public_html/Imagens/file/10124142384.pdfIn PDF document text
    • https://cosonnguyenthanh.vn/webroot/userfiles/files/84036818199.pdfIn PDF document text
    • https://jf-orvalho.pt/userfiles/file/mojiruvapa.pdfIn PDF document text
    • https://sintasyapi.com/img/userfiles/file/90877790304.pdfIn PDF document text
    • https://acrgruppe.de/userfiles/file/49841979259.pdfIn PDF document text
    • http://wxhsbl.com/ckfinder/userfiles/files/20210914_065033.pdfIn PDF document text
    • https://hotelritariccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613bdfa9cd4c8---69656640894.pdfIn PDF document text
    • http://changrung.com/ckfinder/userfiles/files/belifixigaxat.pdfIn PDF document text
    • https://zbmbudomont.pl/userfiles/file/79632874755.pdfIn PDF document text
    • http://www.fotografoeventimilano.com/wp-content/plugins/formcraft/file-upload/server/content/files/161360e5ae1332---42243792521.pdfIn PDF document text
    • http://sungder.com/upload/20432745744.pdfIn PDF document text
    • https://cryptoshift.be/anaeter_capital/siteadmin/userfiles/files/8132184532.pdfIn PDF document text
    • https://lacaune.hu/userfiles/file/9646133420.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/9utg8dirrrp0687ibf5vqpunf2/11823931201.pdfIn PDF document text
    • 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_off0000da50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA50 17680 bytes
SHA-256: 4ca2d5c4c38074c0b862c878edd2502bcd77cd4bef1390e39bab78146bc9dfc7
font_01_sfnt_off0001086a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1086A 10700 bytes
SHA-256: d20c76811394cba773fc52e72d6335d871599053326edde9bdb2a1895fa147e8
font_02_sfnt_off000120f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120F0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1