Malicious PDF — malware analysis report

Static analysis result for SHA-256 b421547007021e1f…

MALICIOUS

PDF

84.7 KB Created: 2021-09-15 13:16:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 90b84647258f6e5b948c33fe739f43fc SHA-1: 7987bbe98dd22da536c63250ae8644711b119e17 SHA-256: b421547007021e1fb0de3cc37bc9720c49e56beaf498d370f7f049cae145297b
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, with heuristics indicating it functions as a link farm on disposable hosting. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious document delivery mechanisms.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://daiichihousing.net/uploads/news_file/70949469900.pdf In PDF document text
    • https://southernwashpros.com/nbloom/fckuploads/file/63991406906.pdfIn PDF document text
    • http://ulleungroadtour.com/FileData/ckfinder/files/20210908_EFE92BECB24E83B2.pdfIn PDF document text
    • http://skoleniridicubrno.cz/ckfinder/userfiles/files/gobumunoretetamegapiri.pdfIn PDF document text
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138534d0199c---41037676156.pdfIn PDF document text
    • http://kkslavicin.cz/sites/default/files/file/92543608652.pdfIn PDF document text
    • http://achilleferolla.it/userfiles/files/babagi.pdfIn PDF document text
    • http://jyjwqj.com/uploadfile/file///2021091322172852.pdfIn PDF document text
    • http://bowenlawmt.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/voxusodoposabotevege.pdfIn PDF document text
    • https://egyediajandekotletek.hu/mvc/userfiles/file/63446673209.pdfIn PDF document text
    • https://economiadecomunion.com/ckfinder/userfiles/files/buditolidiwatijevir.pdfIn PDF document text
    • http://woodwaysindia.com/uploads/lepepadaxavoselowu.pdfIn PDF document text
    • http://cellesekorea.com/ckupload/files/632769040.pdfIn PDF document text
    • http://tgtech-auto.com/userfiles/file/vibixaletoro.pdfIn PDF document text
    • http://emploi.nat.tn/ckeditor/ckfinder/userfiles/files/rewizigiraxituwalijag.pdfIn PDF document text
    • http://helloslow.com/data/userfiles/files/tijalubijuxejeba.pdfIn PDF document text
    • http://transbur.ru/admin/ckfinder/userfiles/files/53326873855.pdfIn PDF document text
    • http://uitetenindex.nl/images/uploads/25667174595.pdfIn PDF document text
    • https://phnews.ro/files/file/80176122435.pdfIn PDF document text
    • http://droneducational.com/admin/userfiles/file/nupuvirusinavonotawabomax.pdfIn PDF document text
    • https://agrilaui.com/userfiles/file/53690338435.pdfIn PDF document text
    • http://www.frank-diagn.hu/userfiles/files/wometanamewezonidis.pdfIn PDF document text
    • https://aiaciran.org/cache/fck_files/file/mugagolip.pdfIn PDF document text
    • http://qdxqw.com/uploadfile/file/58999769621.pdfIn PDF document text
    • http://promocode.lu/userfiles/files/2008197408.pdfIn PDF document text
    • http://msinziniering.com/userfiles/file/lefog.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=how+to+hack+my+eyes+only+passwordPDF 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_off0000e5a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5A3 17248 bytes
SHA-256: dfa8b00bf4cc21518d9a4bc76b1fb57eda9a5f76d881a4fd64430022408ddbe3
font_01_sfnt_off000111be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111BE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000129d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129D5 10968 bytes
SHA-256: 26feeaf7b942521a52ce6798a5de16df5e4ab31e646e8d4213dc335aa41ba169