Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4bb42531d026017…

MALICIOUS

PDF

83.0 KB Created: 2021-09-18 20:30:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 1b8b1b4cfc78e8197a158286fb13dbd3 SHA-1: 463b8ed00620106db4202c13b559c0032bf74e54 SHA-256: b4bb42531d02601780f736118850bf41ce04220249148ee6fe953825bd07facf
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external PDFs hosted on various domains, many of which appear to be disposable or low-reputation. The heuristic 'PDF_RANDOM_URL_LINK' and 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggest a phishing or malware distribution attempt. While no scripts were directly extracted, the nature of the links and the ClamAV detection indicate a malicious intent to redirect users to harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 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://taipeitccia.org/CKEdit/upload/files/lelavulotusobavop.pdf In PDF document text
    • http://babamoleskine.com/files/file/9374263740.pdfIn PDF document text
    • https://driftwoodcc.com/userfiles/files/pajopifewitijosafomol.pdfIn PDF document text
    • http://chaodontuonglai.vn/uploads/ck_upload/files/27929602638.pdfIn PDF document text
    • http://wyadonline.com/userfiles/file/vugegojojuwigipararat.pdfIn PDF document text
    • http://xn----7sbndn5at.xn--p1ai/uploads/files/54157488036.pdfIn PDF document text
    • http://wwstationery.com/files/file/47355149904.pdfIn PDF document text
    • https://webshopplus.nl/app/webroot/files/userfiles/files/soroxogawapi.pdfIn PDF document text
    • https://banderlogclub.ru/Files/file/40281605520.pdfIn PDF document text
    • http://veterinarioassociatopacinidallatorre.eu/userfiles/files/32379925784.pdfIn PDF document text
    • http://bigdoughpizza.com/uploads/files/69712576326.pdfIn PDF document text
    • http://tuanlongland.com/upload/files/pekos.pdfIn PDF document text
    • http://dobraukraina.org/sites/all/sites/dobraukraina.org/files/mizuwolepesivu.pdfIn PDF document text
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/161399b9b8c753---neluxopimafa.pdfIn PDF document text
    • https://lyonsinn.com/nbloom/fckuploads/file/44979133103.pdfIn PDF document text
    • https://www.abrasco.org.br/ckfinder/userfiles/files/doginomobidavepijibulexe.pdfIn PDF document text
    • https://onlinendttraining.com/files/mebaxobizun.pdfIn PDF document text
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/05e7bd09ce7b619fe4616766b45f8bf3/dovegu.pdfIn PDF document text
    • http://baschin-heizung.de/meineBilderAlbertGrundschule/file/543752535.pdfIn PDF document text
    • https://tasleemdubai.com/userfiles/files/66331488841.pdfIn PDF document text
    • http://handinks.com/ckfinder/images_store/files/polisotadodirujubujus.pdfIn PDF document text
    • http://sunriverps.com/data/editor/file/tabovugavonule.pdfIn PDF document text
    • http://sin-hua.org/userfiles/dekedeseredun.pdfIn PDF document text
    • https://kattliv.com/kattliv/admin/userfiles/file/nokena.pdfIn PDF document text
    • https://jdsliquorlocker.com/nbloom/fckuploads/file/25627954417.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=note+s20+vs+iphone+12PDF 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_off0000df76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF76 18164 bytes
SHA-256: c58dfd58cbd41ac479cd581bbc623197106e683216f6d25197461666ff4c7fcc
font_01_sfnt_off00010ecd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10ECD 10376 bytes
SHA-256: 61eb4778ff78a9c5d544125a4763fc2f29717734a2ca45a0689d6bf9fdfbeebe
font_02_sfnt_off0001265a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1265A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1