Malicious PDF — malware analysis report

Static analysis result for SHA-256 13051e0654bd8dd0…

MALICIOUS

PDF

71.8 KB Created: 2021-10-10 23:21:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 717e1d5c62da03d71754153e7cc9ccdf SHA-1: 122bd5c2a87e33315f96369620d87457ac2889c4 SHA-256: 13051e0654bd8dd09ac4829a78ad4b711bc08c2adc61d8070098ceed70b86414
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which point to compromised or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery through these links. The file's structure and the nature of the URLs suggest it's designed to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://synerhu.ru/uplcv?utm_term=student+exploration+magnetism+answers PDF link annotation
    • https://sakura-bashi.com/uploads/files/202109090658227837.pdfIn PDF document text
    • http://parfumland.sk/upl/15357716280.pdfIn PDF document text
    • http://cokhitienvuong.com/uploads/files/fakadulevojazuxedawu.pdfIn PDF document text
    • http://puginternational.com/ckfinder/userfiles/files/24221660656.pdfIn PDF document text
    • https://cs168.tw/upfiles/editor/files/28568302061.pdfIn PDF document text
    • http://allycatering.com/userfiles/naxizefar.pdfIn PDF document text
    • http://sudeoksa.net/userfiles/file/20210913230427.pdfIn PDF document text
    • http://pietrek.com/MARCUS/files/file/56359824688.pdfIn PDF document text
    • http://istanbulballoons.com/ckfinder/userfiles/files/86049983061.pdfIn PDF document text
    • https://fullhousetourism.com/UploadFiles/file/20210929055355188.pdfIn PDF document text
    • http://utcsp2.rustyramone.com/uploads/files/rukibesomirujofewajemuti.pdfIn PDF document text
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/161543b943e21d---mixeturoderirunegopun.pdfIn PDF document text
    • https://lexconsulting.ro/webroot/files/media/lovusadixekari.pdfIn PDF document text
    • http://gsprojekt.eu/userfiles/files/xobeweranitonirugulu.pdfIn PDF document text
    • https://dongytueduc.com/wp-content/plugins/super-forms/uploads/php/files/98e0mf9gchq9gj596gcfna826j/sogipanakewegizazatex.pdfIn PDF document text
    • https://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16155618d84a25---burelajisavujomopazu.pdfIn PDF document text
    • http://euphoriaclub.fun4two.pl/uploads/assets/file/fajovovopevotebu.pdfIn PDF document text
    • https://sledovani3.gpshlidac.cz/www/userfiles/files/77847422886.pdfIn PDF document text
    • https://e-tta.com/app/webroot/userfiles/files/bimawupexabategipefesa.pdfIn PDF document text
    • https://korzo-galeria.hu/files/file/69029081865.pdfIn PDF document text
    • http://4bx.pl/public/file/woguporigavimegepovak.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_off0000b64e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB64E 11096 bytes
SHA-256: d0461558ef07040d24b82566424b5c70ca7c6a4b2b8f0e309e144f8b52e01b31
font_01_sfnt_off0000d009.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD009 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e81b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE81B 16132 bytes
SHA-256: 72edd22f37d8400a272f782b9c9bf17378bc0df5735d9055570de4520be22db5