Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b85b90454953873…

MALICIOUS

PDF

72.3 KB Created: 2021-09-11 17:32:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 1d2e528c5e580616577dca3c0a978a1a SHA-1: 53ad14478aca71f81cf12392a6e432b9bfbec69a SHA-256: 3b85b90454953873578d176e5b3bdde428615f378335f22cd4327594ce101847
126 Risk Score

Malware Insights

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

The PDF file was flagged by a ML classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to numerous distinct domains, many of which are hosted on disposable infrastructure. The embedded URLs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://growmytruck.com/wp-content/plugins/super-forms/uploads/php/files/b1fe55abb38b0d553d5d2cf54bec597f/97326454075.pdf In PDF document text
    • https://carsen.sk/editor_uploads/system/files/71410416301.pdfIn PDF document text
    • http://dellalontra.it/userfiles/files/fezifudi.pdfIn PDF document text
    • http://architettoseneca.com/userfiles/files/kixuzamegafalete.pdfIn PDF document text
    • http://cozycornerexpress.com/uploads/files/bunakog.pdfIn PDF document text
    • http://studioesflores.pl/obrazy/file/wadusipagi.pdfIn PDF document text
    • https://dichvumoinoi.com/ckfinder/userfiles/files/jonuru.pdfIn PDF document text
    • http://hanauhrova.cz/files/dotet.pdfIn PDF document text
    • https://www.xtremefitness.com.au/application/third_party/ckfinder/userfiles/files/ferabagonuzaponanutigu.pdfIn PDF document text
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/161361f6549fe7---dowuvijunomupumifis.pdfIn PDF document text
    • https://destockbaby.com/ckfinder/userfiles/files/95661521958.pdfIn PDF document text
    • http://stitesattorney.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/demidibutirukolaxuse.pdfIn PDF document text
    • https://toscanafantastica.com/userfiles/file/3477782115.pdfIn PDF document text
    • http://www.ih-consultant.com/ckfinder/userfiles/files/milapirufipudi.pdfIn PDF document text
    • http://avvocato-callegaro.it/public/file/wujekumu.pdfIn PDF document text
    • http://0vote.com/ckfinder/files/73172111153.pdfIn PDF document text
    • http://redskap.ru/userfiles/file/zajufewazos.pdfIn PDF document text
    • http://ansonseatery.com/uploads/files/selexemi.pdfIn PDF document text
    • https://perfecthospitals.org/ckfinder/userfiles/files/nusotaru.pdfIn PDF document text
    • https://kermoulin.com/userfiles/file/lijakepeveramaboworopix.pdfIn PDF document text
    • http://jfac.kr/ckfinder/userfiles/files/67163832651.pdfIn PDF document text
    • http://fantacyhandicraft.com/userfiles/file/36014048107.pdfIn PDF document text
    • http://tdvvietnam.vn/webroot/img/files/19860590470.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=the+spike+volleyball+story+apkPDF 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_off0000b665.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB665 10620 bytes
SHA-256: 99464e8185678c3aae7eabe01241c3012e0df8759b6e0c008d39c4494a41f273
font_01_sfnt_off0000ceab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEAB 17592 bytes
SHA-256: 6871dcb451c22a9a68c8222d403dd3731ec1de466adcc99be557cac8645c2b64
font_02_sfnt_off0000fb90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB90 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1