Malicious PDF — malware analysis report

Static analysis result for SHA-256 261d8149866041b3…

MALICIOUS

PDF

79.8 KB Created: 2021-09-16 23:54:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 4616517e48c887c35edf6db2a5323f5d SHA-1: 62b7dbdff8b33d1a9d109741b2c9d7d6f7dd0c6a SHA-256: 261d8149866041b3f1a49259e4f14c8be5b9a3b0fee5a49d4caee33f5ae6bf20
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, specifically phishing or malware distribution. The presence of multiple external URIs and link farm heuristics confirms the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://pistant.ru/uplcv?utm_term=suppression+compte+gmail+sur+android PDF link annotation
    • https://gulceoyunlar.com/calisma2/files/uploads/nowetaxezu.pdfIn PDF document text
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613c368999ba4---83194703802.pdfIn PDF document text
    • http://studioagm.it/userfiles/files/32918687798.pdfIn PDF document text
    • https://thehouseproduction.net/file/vezusufefuko.pdfIn PDF document text
    • https://wsbe17hongkong.hk/_bin/ckfinder/userfiles/files/wopitovemujagomadabutemub.pdfIn PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/1613d4346dd6a8---77753676174.pdfIn PDF document text
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613faebf4c3d0---86956874261.pdfIn PDF document text
    • http://air-ned.com/uploads/files/jujifamowafobujatoxenu.pdfIn PDF document text
    • https://www.esfa.bg/root/ckfinder/userfiles/files/96160701457.pdfIn PDF document text
    • https://labelmarket.pl/data/file/talisufatukado.pdfIn PDF document text
    • http://dd-eng.com/files/files/85564348311.pdfIn PDF document text
    • http://boek.se/bilder_umeny/File/33995563878.pdfIn PDF document text
    • http://big-blue-bus.com/pics/fotos/1/file/91609350415.pdfIn PDF document text
    • http://j-club.eu/userfiles/file/63735065352.pdfIn PDF document text
    • http://iwilldoit.ru/uploads/files/files/dewem.pdfIn PDF document text
    • http://kargo-box.com/uploads/files/23987176144.pdfIn PDF document text
    • https://tonthephunglan.vn/upload/files/87727976396.pdfIn PDF document text
    • https://vrindaindia.com/php/joseph/uploads/file/viloxibiludavefuja.pdfIn PDF document text
    • http://kossuthdigisuli.hu/userfiles/file/80769999221.pdfIn PDF document text
    • https://happyfun.tw/uploads/files/202109151754058633.pdfIn PDF document text
    • http://www.injamal.es/nueva/ckfinder/userfiles/files/fetominedevebusi.pdfIn PDF document text
    • http://bet-balance.com/userfiles/file/53171538622.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_off0000d1a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1A6 18488 bytes
SHA-256: a051298ba6904b1eacb79f89c726af6495e2953470611dadabecb0f262fa7038
font_01_sfnt_off0000ffee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFEE 11032 bytes
SHA-256: c4d7c4ad9585168dfc618213f0703a4c7a0b5e5dc17c00d2d3af716fa46b96e0
font_02_sfnt_off0001195b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1195B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1