Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b11fa61431ed85c…

MALICIOUS

PDF

82.5 KB Created: 2021-09-11 02:44:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 6631ed01b6c01c29527c56f1dfbd5307 SHA-1: efb06c86d715680e6abee32347abc804ba6010bd SHA-256: 4b11fa61431ed85c7bf6d47adbce2e3479edaad17f838cf16f647daad9e56afe
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://infrive.ru/uplcv?utm_term=ocean+nomad+mod+apk+free+craft PDF link annotation
    • http://infosierra.es/images/editor/kalekizepaz.pdfIn PDF document text
    • https://subarini.ro/mm/file/mikavidenobufo.pdfIn PDF document text
    • http://ekorob.pl/userfiles/file/2255222331.pdfIn PDF document text
    • http://kool-house.com/upload/editor/file/54579681529.pdfIn PDF document text
    • http://global-gypsum.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f332c8eebe---raketeguvi.pdfIn PDF document text
    • http://geriatriccarenewjersey.com/userfiles/files/xaveresizatanibesizijaro.pdfIn PDF document text
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/48f02b09a75afbd7900cde0f2856a35e/gorufekegan.pdfIn PDF document text
    • https://nurdagihaber.com/resimler/files/vajonixezuxigisefove.pdfIn PDF document text
    • http://abwva.com/uploads/files/doxatururevoxakila.pdfIn PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/16138112e22285---84983132685.pdfIn PDF document text
    • http://neodev.space/wp-content/plugins/formcraft/file-upload/server/content/files/16135bdce58105---soxafupu.pdfIn PDF document text
    • http://ks-system.co.uk/ckfinder/userfiles/files/keduxekulutifupojebepagez.pdfIn PDF document text
    • http://hytechcommunications.com/userfiles/file/zedukimumajuguvezebiwud.pdfIn PDF document text
    • http://uitvaartverzorgingsindex.nl/images/uploads/zewasibazunuji.pdfIn PDF document text
    • http://kimura-shihoshoshi.com/userfiles/file/koxudasesujukuvaguvit.pdfIn PDF document text
    • http://hotelclinton.it/userfiles/files/bajemumeketaxeda.pdfIn PDF document text
    • https://cqc-material.com/app/webroot/userfiles/files/41735786655.pdfIn PDF document text
    • https://suprastoc.ro/userfiles/file/27507186976.pdfIn PDF document text
    • http://pro-roubenky.cz/UserFiles/File/39665521792.pdfIn PDF document text
    • https://on-call-anatomist.org/ckfinder/userfiles/files/gumemuluroserizovuwofad.pdfIn PDF document text
    • http://ktcz.eu/files/files/12824088384.pdfIn PDF document text
    • http://asia-test.informacittadino.net/media/files/35428915172.pdfIn PDF document text
    • http://macro-e.com/app/webroot/userfiles/files/31657402517.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_off0000d73d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD73D 10592 bytes
SHA-256: 664c88e7cfe812f2263b5d13899688305c8df242e56682fcdbaffd036c29ab5f
font_01_sfnt_off0000ef68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF68 20264 bytes
SHA-256: b77085ed653390526927e65dc8fdc74e63686f98f0dc76af04e26916e65592f1
font_02_sfnt_off000124b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124B8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1