Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d71abca741e42c5…

MALICIOUS

PDF

71.0 KB Created: 2021-09-25 18:19:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 57a6766fc0ec6b684bcc5c24e3c21b4d SHA-1: 2c837292baa08146f25c936fab2362d2fcd37567 SHA-256: 8d71abca741e42c55d417560fe0cf39f9fd65ad57fa5851dafcc5f9ce6ef2be4
156 Risk Score

Malware Insights

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

The file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to potentially compromised or disposable hosting, suggesting a link farm designed to redirect users. The PDF structure and link farm behavior are consistent with phishing or malware distribution lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://chhattisgarhsanskritboard.in/sharpinstitute/images/files/direpiwaxomej.pdf In PDF document text
    • http://vkp.ru/upload/global/file/jusajinirovipov.pdfIn PDF document text
    • http://cabini.it/userfiles/files/59617205271.pdfIn PDF document text
    • http://newkontakt.ru/userfiles/images/file/japozutinorizame.pdfIn PDF document text
    • http://kapalishakti.com/ckfinder/userfiles/files/berosaxolasedona.pdfIn PDF document text
    • http://ekouklid.eu/UserFiles/file/mafonubozabokafokifu.pdfIn PDF document text
    • http://telegid.tv/userfiles/file/jaguxa.pdfIn PDF document text
    • https://harkakotony.hu/UserFiles/file/niredesusajatofu.pdfIn PDF document text
    • http://privateeducation.sg/verzsape/demo/upload/admin/files/96885129004.pdfIn PDF document text
    • https://kaowei.tw/image/files/20210914_040144.pdfIn PDF document text
    • https://amatnieks.com/pictures/image/buwetufonopada.pdfIn PDF document text
    • https://generalaudit.pl/eurostyl/photos/file/25028361.pdfIn PDF document text
    • http://re-media.ru/foto/ck/files/83968004860.pdfIn PDF document text
    • https://virtualpulse.eu/UserFiles/file/vavijubukik.pdfIn PDF document text
    • https://mountmoriahcamp.com/media/tovivo.pdfIn PDF document text
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1614afebb489bb---xizike.pdfIn PDF document text
    • http://paraleumarian.ro/app/webroot/files/userfiles/files/pufoxizotado.pdfIn PDF document text
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/161453a664a177---91701735320.pdfIn PDF document text
    • https://ntct-dz.com/ckfinder/userfiles/files/44125410566.pdfIn PDF document text
    • http://peetersinstallatietechniek.nl/upload/files/beromepakoratudajuja.pdfIn PDF document text
    • http://planet-for-events.de/userfiles/file/79126056070.pdfIn PDF document text
    • https://nsck-cykelmotion.dk/ckfinder/userfiles/files/gazetunesifu.pdfIn PDF document text
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131d6e4aeb7f---kefemu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=fs+14+app+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_off0000b27a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB27A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ca8c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA8C 17432 bytes
SHA-256: fb2a0757b7162aaf8f687fb93e40e6f5c3d12a02fdb6db96910c6af48d4ceffc
font_02_sfnt_off0000f764.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF764 10156 bytes
SHA-256: b5d23d19db97c7a590198e14c476aafd8ebe46aff20bd0f5890445ca496a5b7e