Malicious PDF — malware analysis report

Static analysis result for SHA-256 edba4586a201aa61…

MALICIOUS

PDF

78.5 KB Created: 2021-10-20 20:05:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 9f55894bbbded453e31b56163b076eee SHA-1: d259b25edd8ceea8333bfb403a2392d5ae031030 SHA-256: edba4586a201aa61c7ad3c906a736d8626e7f5ff22a20690af920508515e06dd
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as a phishing trojan. Static analysis revealed multiple heuristic firings indicating the PDF acts as a link farm, with many URLs pointing to disposable hosting and potentially malicious content. The ML classifier also strongly indicated maliciousness. The presence of numerous external links suggests an attempt to redirect users to malicious sites or download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://fitvital.hu/userfiles/files/bodefenojilitosamubifajup.pdf In PDF document text
    • http://stellar-toys.com/ckfinder/userfiles/files/38921841851.pdfIn PDF document text
    • https://seedomoretravel.com/files/files/16604200921.pdfIn PDF document text
    • https://amrapalispot.com/userfiles/file/bexedenevulodubujo.pdfIn PDF document text
    • http://loscogliodifavignana.it/userfiles/files/52038078280.pdfIn PDF document text
    • http://lixupeng.com/uploads/files/ziviko.pdfIn PDF document text
    • http://bortran.com/upload/image/file/20210930051633.pdfIn PDF document text
    • http://valentine.tutaylamhet.com/storage/ckfinder/files/bigobufidojixamanizu.pdfIn PDF document text
    • http://cicm2015.mist.ac.bd/app/webroot/ckfinder/userfiles/files/sigufitepivuro.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1616cf877edbaf---77303133644.pdfIn PDF document text
    • http://manu-transport.com/documents/file/vuloramopumekamiwejede.pdfIn PDF document text
    • https://poganyvolgyi.hu/userfiles/file/mukesuke.pdfIn PDF document text
    • http://freetds.net/userfiles/file/8932205930.pdfIn PDF document text
    • http://ambulatorioveterinariovianello.eu/userfiles/files/75693841521.pdfIn PDF document text
    • http://guojingmall.com/userfiles/file///28636971966.pdfIn PDF document text
    • https://oolong-dining-co.com/webroot/editor-uploads/files/digaxifusuzi.pdfIn PDF document text
    • https://strategieb2b.com/userfiles/file/22146070361.pdfIn PDF document text
    • https://baigiangtoanhoc.com/upload/files/jozadifumitevoro.pdfIn PDF document text
    • https://treasurehunterdetectors.com/ckfinder/userfiles/files/58163050789.pdfIn PDF document text
    • https://ihotel2b.com/upfiles/editor/files/walotunukufowugovokez.pdfIn PDF document text
    • https://sportyou.fr/ckfinder/userfiles/files/wapedevowivaxipukot.pdfIn PDF document text
    • https://nichebearing.leaddeehub.com/userfiles/files/24112373142.pdfIn PDF document text
    • http://forepic.com/_UploadFile/Images/file/78902190460.pdfIn PDF document text
    • http://colorfulmedia.de/fotki/fotki/file/foxuzeligova.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Gsjc/~3/TxADE9PCSUw/uplcv?utm_term=latkes+from+frozen+hash+brownsPDF 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_off0000cf72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF72 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e789.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE789 10676 bytes
SHA-256: b537a5cde839f11a7a22e1f9e0601f27100896e07997a78c20b6e3c397f86700
font_02_sfnt_off0000fff5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFF5 17100 bytes
SHA-256: e19a56536bd3bda70ea3f97fa47e2003a3476d5611b6a20cc22a40d5e79fe6ee