Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b5592a02e7fef19…

MALICIOUS

PDF

77.3 KB Created: 2021-10-05 19:17:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 000a40ab0428c308a721652e0a6727cb SHA-1: e13750f74b25209ac42e5b71497bfad385d8a6ff SHA-256: 4b5592a02e7fef19a45df88434bdbfac8eea174d17ea757776dd3c4b8a7c493e
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised CMS upload directories or are hosted on disposable domains, indicating a link farm or SEO spamming operation. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://sakulchaiplace.com/Uploads/file/larikaxa.pdf In PDF document text
    • https://www.bussmann-tiefbau.de/ckfinder/userfiles/files/7742832919.pdfIn PDF document text
    • http://www.putnamtaxi.net/wp-content/plugins/formcraft/file-upload/server/content/files/16149ad4f4f033---vipanejigime.pdfIn PDF document text
    • https://psychotherapie-coeppicus.ch/userfiles/files/davovuw.pdfIn PDF document text
    • http://www.rebranded.tv/wp-content/plugins/formcraft/file-upload/server/content/files/1613cf17dc5a60---70802458030.pdfIn PDF document text
    • https://myshalewell.com/userfiles/file/rowad.pdfIn PDF document text
    • https://event-connections.net/wp-content/plugins/formcraft/file-upload/server/content/files/1615baebf8852e---padodatuzab.pdfIn PDF document text
    • http://leebyunghun.org/new/upload/board/files/nodapasagatewanuxaramiga.pdfIn PDF document text
    • http://mobitransjogja.com/files/zikodamufefowozuzufujodig.pdfIn PDF document text
    • http://elfobchod.cz/foto/Image/file/geveluzosujegosofowope.pdfIn PDF document text
    • https://curvy.tw/upload/files/86510809671.pdfIn PDF document text
    • https://surupaceanu.ro/ckfinder/userfiles/files/71897316178.pdfIn PDF document text
    • https://rumahbaruku.com/contents/files/revuxofogag.pdfIn PDF document text
    • http://greenld.com/userfiles/fojuxosesulozumoxodexawid.pdfIn PDF document text
    • https://ncsccalgary.com/userfiles/files/90693920039.pdfIn PDF document text
    • http://handsonmontessoripk.com/userfiles/files/4340664181.pdfIn PDF document text
    • http://congress.bpv.su/content/files/files/27751501665.pdfIn PDF document text
    • https://www.adelaarenergy.com/wp-content/plugins/super-forms/uploads/php/files/n2v582b1vhmqkl488tsd7nhlig/97089872754.pdfIn PDF document text
    • http://www.farmaciabergua.com/userfiles/files/wanunuzujigeme.pdfIn PDF document text
    • https://markiza-trade.ru/admin/ckfinder/userfiles/files/56206386003.pdfIn PDF document text
    • http://harissarantis.com/userfiles/files/15982475692.pdfIn PDF document text
    • https://www.thic.net/plugin/ce1/ckfinder/userfiles/files/68033535872.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=find+the+lcm+of+18+24+and+32PDF 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_off0000c55f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC55F 11080 bytes
SHA-256: 4763c661768325dab594083abeeb44a487c053d6905c8e762bec8f0e2db21817
font_01_sfnt_off0000df12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF12 18584 bytes
SHA-256: 04a3131370943c8797cf8c1cc7034cb50c25611b12bc5507491d2009e1a2a154
font_02_sfnt_off00010f5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F5F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1