Malicious PDF — malware analysis report

Static analysis result for SHA-256 2813136aeb64ca37…

MALICIOUS

PDF

81.7 KB Created: 2021-09-19 05:48:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 1ac75a70f3db2a38369013c73163d0d0 SHA-1: dd85d5e4c7b8fc236ed927ba04b9a04d4dc1d203 SHA-256: 2813136aeb64ca3797056a0585be6785c0598d24c809a0720f8972610d91c331
126 Risk Score

Malware Insights

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

The PDF document was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically points to the document acting as a link farm, with numerous distinct hosts and UTM term redirectors, suggesting a phishing or malware distribution scheme. The embedded URLs, despite one being confirmed benign, are part of this larger pattern of directing users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

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 http://papianiarch.it/userfiles/files/21862681955.pdf In PDF document text
    • http://mamolenasnc.it/userfiles/files/50979848462.pdfIn PDF document text
    • http://mrs724.ir/basefile/drtiketcom/files/silupudejabikugugugafesi.pdfIn PDF document text
    • http://hotelborgodeipoeti.com/userfiles/files/10821943683.pdfIn PDF document text
    • https://tranduongauto.com/app/webroot/files/images/pages/files/gidinuxagiru.pdfIn PDF document text
    • http://goldenmallbiotech.com/upload/files/99208847091.pdfIn PDF document text
    • http://antitumor.org/filespath/files/20210906022247.pdfIn PDF document text
    • https://strategieb2b.ca/userfiles/file/16506409419.pdfIn PDF document text
    • http://usaoxin.com/userfiles/2021-9/file/93332707773.pdfIn PDF document text
    • http://cn-biyoute.com/d/files/83517657839.pdfIn PDF document text
    • https://stalbeckers.nl/userfiles/image/file/24225936677.pdfIn PDF document text
    • https://k85shj16h-561lt.com/contents/files/67510424543.pdfIn PDF document text
    • https://licorne-hotel-restaurant.com/userfiles/file/28085569255.pdfIn PDF document text
    • http://rabwork.com/media/file/serogizov.pdfIn PDF document text
    • https://noukos.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16144de7d0711e---58262016909.pdfIn PDF document text
    • https://www.sexualaufklaerung-schule.ch/ck/ckfinder/userfiles/files/vaxetamazevalakupufa.pdfIn PDF document text
    • http://express-service-auto.fr/ckeditor/ckfinder/userfiles/files/29782171833.pdfIn PDF document text
    • http://furniture83.com/upload/files/jivafuge.pdfIn PDF document text
    • https://vitanov.rs/files/11871575698.pdfIn PDF document text
    • http://tlumacz-lipno.pl/pdrzewiecki/files/kesefumepete.pdfIn PDF document text
    • http://pokeocncafe.com/uploads/files/gemitejusej.pdfIn PDF document text
    • https://www.informacion-indoorclub.com/boletines/img/file/xanikodikiter.pdfIn PDF document text
    • http://billedbutikken.dk/articlefiles/file/70276604570.pdfIn PDF document text
    • http://sangtaoad.com/uploads/userfiles/file/viwunupegagapipalogu.pdfIn PDF document text
    • https://mavismanagement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ef94cbf6a0---gojifagataziv.pdfIn PDF document text
    • http://tienhasteel.com/app/webroot/upload/files/satobe.pdfIn PDF document text
    • http://kenhuffbuilders.com/userfiles/file/81124314528.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=vidmate+old+version+2.28+downloadPDF 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_off0000d236.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD236 20712 bytes
SHA-256: 4c726a07d6dec17f5b18044200682f1a0e520b64f7e4b4989df33618368d2006
font_01_sfnt_off000107c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107C1 10924 bytes
SHA-256: de120ce1f901ea2806062858206a44c6b165c41c9038bfdc202421cc01f2f095
font_02_sfnt_off00012122.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12122 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1