Malicious PDF — malware analysis report

Static analysis result for SHA-256 1609282c45bbd208…

MALICIOUS

PDF

84.3 KB Created: 2021-09-06 01:32:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 83d48b27975e85ff59cdd7cdd2b2dee3 SHA-1: d32a6c6839cd5e8f8a5ffa4450e8d5cf5ae0747b SHA-256: 1609282c45bbd20837cb466e292c86ab0eba714a982c2ce03f132e564b3d79fb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous URLs pointing to disposable hosting and compromised CMS uploads, suggesting a link farm designed to redirect users to malicious sites. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' further supports this, indicating the PDF's primary function is to act as a lure for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://smidgel.ru/uplcv?utm_term=tratado+de+endocrinologia-pdf+download PDF link annotation
    • http://hocikto.info/userfiles/file/judurodusetilujevebofo.pdfIn PDF document text
    • http://euro520.net/userfiles/file/1625660362535520807.pdfIn PDF document text
    • https://akapacha.com/userfiles/file/kinisomaxaxazafek.pdfIn PDF document text
    • http://kme-kme.cz/files/file/39462084560.pdfIn PDF document text
    • http://ckrestaurantgroup.com/ckfinder/userfiles/files/modenil.pdfIn PDF document text
    • http://mgocsm.in/userfiles/file/39153448988.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611d111dc6def---biwujenibapubefulaju.pdfIn PDF document text
    • http://fullx.net/files/tefavowap.pdfIn PDF document text
    • https://ruxthai-guesthouse-chiangmai.com/ckfinder/userfiles/files/pinizimodedefurofup.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/mk8pe25sj2c69pae3fuddgq0r5/62278307245.pdfIn PDF document text
    • http://pune-india.info/userfiles/file/digivabuv.pdfIn PDF document text
    • https://atl-50.com/files/file/84910819006.pdfIn PDF document text
    • http://staropolski.net/Upload/file/wepeluso.pdfIn PDF document text
    • http://abarappresentanze.it/userfiles/files/39360954481.pdfIn PDF document text
    • http://symbioticlifetech.org/attfile/fckimg/file///20210619215716_786682298.pdfIn PDF document text
    • https://residenciasanamaro.es/userfiles/files/kejufebuxalupam.pdfIn PDF document text
    • http://dobrasekacka.cz/userfiles/file/2989475911.pdfIn PDF document text
    • http://csc0311.com/userfiles/file/20210807130018_r7pj15.pdfIn PDF document text
    • http://chistogood.ru/admin/ckfinder/userfiles/files/farum.pdfIn PDF document text
    • http://altelaw.com/uploads/image/file/84104647062.pdfIn PDF document text
    • https://seedomoretravel.com/files/files/84747684259.pdfIn PDF document text
    • http://heatherjansch.com/ckfinder/userfiles/files/tuxonar.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1609c1dfbb8403---18896938450.pdfIn PDF document text
    • 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_off0000df44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF44 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f756.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF756 20340 bytes
SHA-256: d748d185bdf6770b696997595db594575dd1d8c13afeaaa4df89a5715350495c
font_02_sfnt_off00012b5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B5E 10712 bytes
SHA-256: c5a7ce5e0f91bdb0414696f18475ea06e50f91d38e249aeab2fa799bd0887f0e