Malicious PDF — malware analysis report

Static analysis result for SHA-256 61cf586e04fd736a…

MALICIOUS

PDF

84.3 KB Created: 2021-10-18 11:31:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: adc8a24379729ee33a468156a61e8eef SHA-1: b2678ece3bc9a06991336d3f9ec0b38fc4d08992 SHA-256: 61cf586e04fd736a7851cda9aa9be9b6633645a82dbd1bdd2ed6c71ba8404fce
156 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous URLs pointing to external sites, several of which are hosted on compromised WordPress installations. This suggests a tactic to distribute malicious content or manipulate search engine results.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://www.pal-kont.hu/wp-content/plugins/super-forms/uploads/php/files/01abb7b1ce40e69c7ddd096d2355a530/kisadubu.pdf In PDF document text
    • http://proclima-membranes.ru/userfiles/file/xasadenovedigetuzoronujon.pdfIn PDF document text
    • http://sosonomo.com/ckfinder/userfiles/files/97395050154.pdfIn PDF document text
    • http://www.advancedevents.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1615ce7316c669---zapevanimizowilirarasogib.pdfIn PDF document text
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613240ce179ea---detaserama.pdfIn PDF document text
    • http://bahia-group.com/ckfinder/userfiles/files/nepajutupot.pdfIn PDF document text
    • http://doanekeyes.com/userfiles/docs/bezibovesezosameke.pdfIn PDF document text
    • http://kingsap.com/file_media/file_image/file/20399140036.pdfIn PDF document text
    • http://tv-sat.cz/userfiles/file/91665041879.pdfIn PDF document text
    • http://danies.ru/ckfinder/userfiles/files/ganipofenalada.pdfIn PDF document text
    • https://nieruchomosciprzetargi.pl/files/file/91444967571.pdfIn PDF document text
    • https://xetnghiemadndanang.com/upload/userfiles/files/gifazijepijuzu.pdfIn PDF document text
    • http://gibkrakow.pl/uploads/files/57237672162.pdfIn PDF document text
    • http://porebaw.niedzwiedz.pl/upload/File/17379910202.pdfIn PDF document text
    • http://xinnethk.com/userfiles/file/4073727090.pdfIn PDF document text
    • http://alphasigmaoverseas.com/userfiles/file/tegovumusufigafutusis.pdfIn PDF document text
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/16131732cbe230---vajadi.pdfIn PDF document text
    • http://sanmorales.es/userfiles/files/1853373122.pdfIn PDF document text
    • http://asid.rw/userfiles/file/dowelixafiba.pdfIn PDF document text
    • http://mcutech.net/files/4386365839.pdfIn PDF document text
    • https://thegioibaobicarton.com/Images_upload/files/satovemexibiroborolubin.pdfIn PDF document text
    • http://gains.kmvindia.com/ckfinder/userfiles/files/18337112423.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/22b2c91d14c1521609abd41daa52ead2/89421643874.pdfIn PDF document text
    • http://monthclean.com/uploads/files/202110091623434521.pdfIn PDF document text
    • https://flylights.pl/wp-content/plugins/super-forms/uploads/php/files/n17lsh0r92khplircq5epp8gcv/rorawapivufewatir.pdfIn PDF document text
    • http://feedproxy.google.com/~r/Xvkpad/~3/Z3ufxtS7Wvw/uplcv?utm_term=i+am+a+consuming+firePDF 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_off0000e800.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE800 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010012.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10012 17032 bytes
SHA-256: 4206dd229a50196bdda97b701570d001fba899198f27d73d29b8a15fd856d15c
font_02_sfnt_off00012bf1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12BF1 10584 bytes
SHA-256: c73a61868a31ec000c26faf8121e0baceb430c9f700547aa0dec83dbc125a312