Malicious PDF — malware analysis report

Static analysis result for SHA-256 2b7f8cba979948c2…

MALICIOUS

PDF

87.6 KB Created: 2021-08-03 13:07:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-02
MD5: fc879dd55a65ece50639bc5a5d51078c SHA-1: 3e985cca395e2c9d9fe06c06fdfa23d3531934ef SHA-256: 2b7f8cba979948c205e30d9bead6544b737116c89b17011db67570cc15bf7b71
96 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • 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://vaytieudungtragop.com.vn/wp-content/plugins/super-forms/uploads/php/files/g8f107dhvdmrmfjsokrjnk74g2/79211781752.pdf In PDF document text
    • https://deltagroup.bg/uploads/file/bezidekusukopisivam.pdfIn PDF document text
    • http://sarljarry.fr/userfiles/file/87795448220.pdfIn PDF document text
    • https://www.bluegreenshouseboats.in/wp-content/plugins/formcraft/file-upload/server/content/files/160c9e000e88bc---ritososubuvigaraja.pdfIn PDF document text
    • https://medicinasolidale.org/wp-content/plugins/super-forms/uploads/php/files/10457f8c678dda4548ed58bab10fa3b8/32886188511.pdfIn PDF document text
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/160a9610f7ed5b---89467699353.pdfIn PDF document text
    • https://turismopontevedra.com/ckfinder/userfiles/files/2448823775.pdfIn PDF document text
    • http://school19-zav.ru/userfiles/file/12521122343.pdfIn PDF document text
    • http://naturallabs.de/userfiles/file/39981249123.pdfIn PDF document text
    • http://rusiuojigalvoji.lt/wp-content/plugins/formcraft/file-upload/server/content/files/1608173d1ee0ec---37022768544.pdfIn PDF document text
    • http://traditionsradio.com/wp-content/plugins/super-forms/uploads/php/files/nr3q317o99l2vi9aomn4ae0d74/wutoralina.pdfIn PDF document text
    • https://kantankacreative.com/wp-content/plugins/super-forms/uploads/php/files/9e411dd45d1e8f3641eb16b9509830e0/50283588899.pdfIn PDF document text
    • https://shayangroup.net/wp-content/plugins/super-forms/uploads/php/files/65df9adba8ad67fb1803dc04cfacb714/64245092709.pdfIn PDF document text
    • https://skazkavdom.com/wp-content/plugins/super-forms/uploads/php/files/e2a763e0c1bbed504173c925f5b22840/jovepasekijawosagoloxus.pdfIn PDF document text
    • http://www.celso.org/download/76848761302.pdfIn PDF document text
    • http://geredekombiservisi.com/userfiles/file/90002302411.pdfIn PDF document text
    • http://deurenhanger.nl/userfiles/file/zudomumeludejipifuw.pdfIn PDF document text
    • https://sasalidayanisma.org/uploads/file/somizidukositidif.pdfIn PDF document text
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/1609ca7980b716---xelaburuwirog.pdfIn PDF document text
    • http://chinocorporatechallenge.com/clients/6216/File/mobitijadogugamavotijik.pdfIn PDF document text
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/beafcd26ab72f834bffb6ad9f6dd895b/watawumavunivutiruz.pdfIn PDF document text
    • http://ne-moloko.ee/wp-content/plugins/super-forms/uploads/php/files/8b5192cc63d505cdf80358012f358570/kizevitawifapedesagi.pdfIn PDF document text
    • http://www.vikingmaterials.com/img/kidadiwaroxodepinoru.pdfIn PDF document text
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608095e0908cf---runov.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=how+to+install+microsoft+office+2016+windows+10PDF 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_off0000eff8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFF8 11176 bytes
SHA-256: 21159a0eb363127c9b61dd6454265f8d6e080ab8bcf79289a4082d588741f924
font_01_sfnt_off00010a38.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A38 16992 bytes
SHA-256: b2508e5079439a734556ea2f8b8da683d9dddc2fe9438b7df3fdcc329a0cca22
font_02_sfnt_off0001367a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1367A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1