Malicious PDF — malware analysis report

Static analysis result for SHA-256 e3fb4eff5a586261…

MALICIOUS

PDF

81.8 KB Created: 2021-09-09 04:57:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 505006d50916b51776de28d1b53f3c24 SHA-1: e509b49f8096874699cc550a9966fb9bcef4b827 SHA-256: e3fb4eff5a586261da722e28db5d5cfb7db55b4a81854222657e4d8ac21e00d8
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm. It contains numerous URLs, many pointing to compromised websites or disposable domains, suggesting an attempt to lure users to malicious content. The presence of external URI heuristics and compromised CMS upload links further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 https://gonguyenkhoi.vn/upload/files/mofuladuwugometaxe.pdf In PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/8bba9186da4edd629fd17155b4493f61/50957863529.pdfIn PDF document text
    • https://digireg.ch/upload/sovudexasu.pdfIn PDF document text
    • http://budka39.ru/files/19507152374.pdfIn PDF document text
    • http://agarimo.com/archivos/archivos/pobubewi.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/161341a277ff96---82440205831.pdfIn PDF document text
    • https://xn--psg-9lac.hu/files/files/sufubalosojadi.pdfIn PDF document text
    • http://firstcuwire.com/file_media/file_image/file/gugafewaxifabawodi.pdfIn PDF document text
    • https://emilline.dk/ckfinder/userfiles/files/29778963478.pdfIn PDF document text
    • http://vhshf.de/File/5538631768.pdfIn PDF document text
    • http://chukgoobok.com/files/fckeditor/file/3860144075.pdfIn PDF document text
    • http://veganogle.es/uploads/ckfinder/files/94645244271.pdfIn PDF document text
    • http://lovelyspa.net/ckfinder/userfiles/files/438073041.pdfIn PDF document text
    • https://mudraconsultancy.com/uploads/files/guzam.pdfIn PDF document text
    • http://retailcop.ca/files/momumibedeb.pdfIn PDF document text
    • http://sportsbettingconsultants.net/cote_dor_import/admin/ckfinder/userfiles/files/zorekavujaremorepi.pdfIn PDF document text
    • https://ecoinkworld.com/wp-content/plugins/super-forms/uploads/php/files/0b9ff3745826d9294792de16b99f41b1/51250661860.pdfIn PDF document text
    • http://bakefruit.com/uploads/files/202109040902277714.pdfIn PDF document text
    • http://uptownchantilly.com/uploads/files/fefepowijevotafisegatuz.pdfIn PDF document text
    • http://ipllaser.in/uploads/92740505430.pdfIn PDF document text
    • https://dudikom.pl/userfiles/file/tonozopexamazetamalum.pdfIn PDF document text
    • http://nwatchonline.net/userfiles/file/19562748629.pdfIn PDF document text
    • http://phuvuongcorp.com/luutru/files/kegise.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=sms+dark+modePDF 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_off0000d1bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1BD 10236 bytes
SHA-256: a0ba78db03f11bdd9bd72c251204e344f97beb7e66447dd6c4707208341cb849
font_01_sfnt_off0000e8bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8BB 21600 bytes
SHA-256: d3ffa4a4f953da812c187e7d0545aca409ea9f6ef7fdb456d552ed5045c13844
font_02_sfnt_off0001219d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1219D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1