Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5444ad8a29aabf3…

MALICIOUS

PDF

91.6 KB Created: 2021-09-21 13:01:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: ffdb939107ba7832c8afae6cf573e372 SHA-1: 40d456f14b4af5fece2e0c6ccc4b37bc5a5eac35 SHA-256: a5444ad8a29aabf399ac57ff4a0e62c80a4526f060ae41f0de685695514b0e88
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple links to external resources, with several heuristics indicating a link farm hosted on disposable domains. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the presence of numerous suspicious URLs points to a downloader or redirector pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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 http://effekt-film.de/files/file/zowuwurebotir.pdf In PDF document text
    • http://thietbibepnhahang.net/media/files/83399419077.pdfIn PDF document text
    • http://ronaldtan.nl/images/photo/jolesiladosekobuber.pdfIn PDF document text
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ba478ec196---nuzelo.pdfIn PDF document text
    • http://www.contal-farmer.com/uploads/files/46466985475.pdfIn PDF document text
    • http://niengrangchuyensau.com/upload/contentFile/file/8444489970.pdfIn PDF document text
    • http://abogarestudio.com/userfiles/file/kikazulujabem.pdfIn PDF document text
    • http://medica-brno.com/files/mudizufinonu.pdfIn PDF document text
    • http://kxqcgs.net/filespath/files/20210904023734.pdfIn PDF document text
    • http://abarappresentanze.it/userfiles/files/47907335995.pdfIn PDF document text
    • http://ark-mr.com/data/home/qxu2063190031/htdocs/uploadfile/files/53510403847.pdfIn PDF document text
    • https://www.vita-organic.eu/admin/ckfinder/userfiles/files/30776615355.pdfIn PDF document text
    • http://signauction.net/userfiles/file/78879563914.pdfIn PDF document text
    • http://kehlux.lu/userfiles/files/59280219230.pdfIn PDF document text
    • http://dar-tom.pl/userfiles/file/gegojitesa.pdfIn PDF document text
    • http://usairsprings.com/userfiles/file/sikokovusen.pdfIn PDF document text
    • https://www.breastcancerfoundation.in/wp-content/plugins/super-forms/uploads/php/files/9639473dc117630becb0c5357fcbbac2/85089996511.pdfIn PDF document text
    • http://fence-alarm.com/userfiles/files/pegor.pdfIn PDF document text
    • http://rialta.ie/userfiles/files/70383321790.pdfIn PDF document text
    • https://www.twibiotech.com/plugin/ce1/ckfinder/userfiles/files/63882362019.pdfIn PDF document text
    • https://verlauf-ekb.ru/admin/ckfinder/userfiles/files/52067804511.pdfIn PDF document text
    • http://monticellotownship.org/userfiles/file/42602393033.pdfIn PDF document text
    • http://lucidarepavimentimarmogenovaealessandria.it/userfiles/files/83263265320.pdfIn PDF document text
    • http://hb-hospital.com/file_upload/fck_upfile/file/23634073875.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=android+clip+studioPDF 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_off0000fbe6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBE6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000113fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113FD 10296 bytes
SHA-256: f761ec38334fa328d32c0a1e61b2e6a5c37e38cb8863d3e34268c1de03ed799f
font_02_sfnt_off00012b3c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B3C 20048 bytes
SHA-256: d6df6604693badf5508dc93a5f6fafcddb87b5ade32d4d202bf3075fa232b59b