Malicious PDF — malware analysis report

Static analysis result for SHA-256 73645171e4a5c1ca…

MALICIOUS

PDF

84.7 KB Created: 2021-08-23 10:24:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 105b4262543d5368893ceaa087c88a8a SHA-1: cdc8c2d617f17aa096d5a9a1455c96c7ded5270f SHA-256: 73645171e4a5c1ca0a4395cf2c7952c93ec26116acca96610633390d3e87a33d
156 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the link farm behavior and heuristic firings.

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://vetranhtuong.info/luutru/files/wodelek.pdf In PDF document text
    • https://cremeconferences.com/wp-content/plugins/super-forms/uploads/php/files/ab50d6987c068fc35455fe9c467a4db0/8501061851.pdfIn PDF document text
    • http://baschin-heizung.de/meineBilderAlbertGrundschule/file/misalom.pdfIn PDF document text
    • https://prosegik.com/wp-content/plugins/super-forms/uploads/php/files/943a86fd8a6c2730c427c2e0b07b9f41/zavupesax.pdfIn PDF document text
    • http://triumphtoday.org/wp-content/plugins/formcraft/file-upload/server/content/files/16110a76a3b0e9---1820758681.pdfIn PDF document text
    • https://law.com.sg/wp-content/plugins/super-forms/uploads/php/files/8f205629658f2ce906bc97cabe405f97/bamitojuluja.pdfIn PDF document text
    • http://solis.altrodesign.eu/ckfinder/userfiles/files/futubefogidojabipopive.pdfIn PDF document text
    • https://wroclawmodelshow.pl/ckfinder/userfiles/files/parimejaliribozuzegixuk.pdfIn PDF document text
    • http://hesexpo.com/img/editor/image/file/sexapumimanotanevuv.pdfIn PDF document text
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1606d263746c1a---64730980766.pdfIn PDF document text
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078710e2c0e1---zopadevijovixisuromusuni.pdfIn PDF document text
    • http://klasykarozrywki.pl/public/images/fck/file/redusapa.pdfIn PDF document text
    • http://scheiden-maassluis.nl/uploads//file/runonenedaso.pdfIn PDF document text
    • http://parkhigh65.com/clients/4970/File/46486418528.pdfIn PDF document text
    • http://abwmechanicsville.com/uploads/files/9182769072.pdfIn PDF document text
    • https://couvreur-hautdoubs.fr/internet_new/images_et_fichiers//file/tepol.pdfIn PDF document text
    • https://marjoyunlar.com/calisma2/files/uploads/95732963712.pdfIn PDF document text
    • http://funagamex.vn/PhuongNamGroup/userfiles/files/57930503218.pdfIn PDF document text
    • https://ajitcoatings.com/uploads/33741275260.pdfIn PDF document text
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/160944794261cf---wemozisiliweburafafakeg.pdfIn PDF document text
    • https://daxitrip.com/basefile/daxitripcom/files/diwawaxexakila.pdfIn PDF document text
    • http://wypelnienia.kratex.pl/wp-content/plugins/super-forms/uploads/php/files/f3b97da4d8cb96a36bb142010f7afa2b/19185950935.pdfIn PDF document text
    • http://orchid-daikanyama.com/userfiles/file/beliba.pdfIn PDF document text
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e650460de48---natedufage.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=foreshadowing+in+life+of+piPDF 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_off0000e643.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE643 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fe5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE5A 10740 bytes
SHA-256: 94dae30c42ad8a57f6bb801dcb12951bcf62a9193e212d0546ac7e84397c7d08
font_02_sfnt_off000116c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116C5 17652 bytes
SHA-256: 6b7ba3c8fa73105d370435a52317171474e8729aba76e304d33b7c9b400ec005