Malicious PDF — malware analysis report

Static analysis result for SHA-256 35c34d8f643e5ae0…

MALICIOUS

PDF

81.0 KB Created: 2021-09-16 04:28:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 22628a188d8a593bd0d7ec4c132cc296 SHA-1: 13b69d7f50aba250f9416dd75bf603f78113847c SHA-256: 35c34d8f643e5ae06d4d90b53a43a13a8020fa10fd7573a32f7dfd1338118b20
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The presence of multiple external URIs and link farm heuristics supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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 http://9y.bfage.com/upload/files/20210916055245.pdf In PDF document text
    • http://giga.sk/storage/file/24391872352.pdfIn PDF document text
    • http://immobilieninvestors.de/userfiles/file/98124741082.pdfIn PDF document text
    • http://freetds.net/userfiles/file/wusomubexinovewegukudu.pdfIn PDF document text
    • http://gzbaosui.com/uploadfile/files/dasijejevuw.pdfIn PDF document text
    • https://rafautama.com/uploads/file/65911171124.pdfIn PDF document text
    • http://chelseafoodmart.com/uploads/files/76486957156.pdfIn PDF document text
    • https://prolocolidodisavio.org/ckfinder/userfiles/files/12012509570.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/16134e968e5845---wisafufefugowonuwidemal.pdfIn PDF document text
    • https://harshahometutors.com/uniformkontakt/userfiles/image/files/nizesusobamukijajipotisev.pdfIn PDF document text
    • http://daechienglishpark.com/ckfinder/userfiles/files/41211344142.pdfIn PDF document text
    • http://aodaiminhhanh.com/app/webroot/uploads/files/fesexuzofov.pdfIn PDF document text
    • https://henuopack.com/d/files/19696500575.pdfIn PDF document text
    • http://aeon-dev.com/uploads/files/202109100420163408.pdfIn PDF document text
    • https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/huciin3qq67ln6ucjid3ng492h/11342207286.pdfIn PDF document text
    • https://www.casestilistas.es/ckfinder/userfiles/files/fegumekida.pdfIn PDF document text
    • https://ottopianos.nl/files/fuxebikigo.pdfIn PDF document text
    • http://www.pes.edu.mn/ckfinder/userfiles/files/20334736750.pdfIn PDF document text
    • https://cmottaviproductive.it/uploads/file/vojenovejikij.pdfIn PDF document text
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613394e4449ef---57362198718.pdfIn PDF document text
    • https://moma-restaurant.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135f63eb8851---petapitoduxixiritudof.pdfIn PDF document text
    • http://2rent.gr/userfiles/file/77876688234.pdfIn PDF document text
    • https://devcons.org/uploads/userfiles/files/fonuxowogobewagomisiluvef.pdfIn PDF document text
    • https://tdemo.order-pro.com/ckfinder/userfiles/files/15264323570.pdfIn PDF document text
    • https://zapcdn.space/web/img/podborky/files/31218225987.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=blocking+sites+on+androidPDF 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_off0000d875.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD875 17536 bytes
SHA-256: a5aac13df2a57eecabc2055bf98c180e90fd3d7798ba9821f1e0aa109b24d6c4
font_01_sfnt_off0001061b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1061B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011e32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E32 10692 bytes
SHA-256: b0da2dc185ff88340d8dd05f4ee0163de4bc003b7b2e787f103072ba5cabdd0f