Malicious PDF — malware analysis report

Static analysis result for SHA-256 af6317331108b5b3…

MALICIOUS

PDF

118.7 KB Created: 2021-08-23 13:11:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 6ec333a21801e0d8d9142ebdad2a0f40 SHA-1: c7a6f79effd1de2119af2b18f31423e5e85d1346 SHA-256: af6317331108b5b37a5767f4c8dc2503789dfbb826b9a6b06cbb64ded6e9cb7c
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to compromised or disposable hosting, suggesting a phishing or malware distribution scheme. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond the heuristic findings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://www.tsahimmongol.com/uploads/images/files/51891771343.pdf In PDF document text
    • https://dbjadow.pl/attachments/file/44469978034.pdfIn PDF document text
    • https://canadianrelocation.net/wp-content/plugins/formcraft/file-upload/server/content/files/160dddf2fee5c1---83116416859.pdfIn PDF document text
    • http://esangsok.com/upfile/files/puluxasigoxiwusadegevanat.pdfIn PDF document text
    • http://bienbao.org/uploads/files/66808299838.pdfIn PDF document text
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16112f41a19367---50759922703.pdfIn PDF document text
    • https://gresathouse.com/wp-content/plugins/super-forms/uploads/php/files/851ec807b6512767812c19ebbadcf34b/22405207317.pdfIn PDF document text
    • https://minhvuongthuphap.com/upload/ck/files/24835454522.pdfIn PDF document text
    • http://tradeweb.es/userfiles/file/gevozokeduwefumixeset.pdfIn PDF document text
    • https://bomberosdenavarra.com/userfiles_nexo/files/rovebavarezuvad.pdfIn PDF document text
    • http://urbancollab.com/userfiles/Proj_Name//files/radebedabijobinakamone.pdfIn PDF document text
    • https://havanic.com/cache/fck_files/file/tufap.pdfIn PDF document text
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16073c1b168a03---9364243302.pdfIn PDF document text
    • http://canyonoaksmtg.com/~duckdi5/canyonoaksmtg.com/content/file/tajejufovefosafurojina.pdfIn PDF document text
    • https://5udua.com/contents//files/gijinefovidotumowejugos.pdfIn PDF document text
    • http://kfbma.org/files/fck/file/velugom.pdfIn PDF document text
    • https://tempatpasang.com/contents//files/55841378508.pdfIn PDF document text
    • http://alrehabourhome.com/userfiles/files/fivodaxobefeniw.pdfIn PDF document text
    • http://ecohort.com/userfiles/files/mizumarasujunodawabu.pdfIn PDF document text
    • http://minuspk.ru/minuspk.ru/userfiles/file/puvopevoxefap.pdfIn PDF document text
    • http://kondicionery-noginsk.ru/upload_picture/file/1489213105.pdfIn PDF document text
    • https://fenicia.uy/fenicia.com.uy/uploads/files/24905701831.pdfIn PDF document text
    • https://erdenet.mn/userfiles/file/98529052478.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=which+of+the+following+statement+is+false+for+mass+spectroscopyPDF 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_off0001674c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1674C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00017f63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17F63 11120 bytes
SHA-256: 900f3bcb23036a3485bbe6876fcb12c5f89e037e3672ea67c3f5b2e74a069f98
font_02_sfnt_off00019939.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19939 19072 bytes
SHA-256: d0012a83613ad76d62ef417636c9d1704daec5b5139ba08dd0cdaf4d7e0e82e3