Malicious PDF — malware analysis report

Static analysis result for SHA-256 b561743e06f33d20…

MALICIOUS

PDF

80.5 KB Created: 2021-09-16 18:21:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: cc9135355a2aaa1a4bbba0eb78143f6a SHA-1: 317f6c35dadf10d78b1dc49f0eadd6bde40ebbb7 SHA-256: b561743e06f33d206f5cc2540ee3b023cea82da2c362c91e9f68e8e129c9d372
156 Risk Score

Malware Insights

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

The PDF contains a link farm directing to numerous other PDF files, many hosted on domains flagged as potentially compromised or disposable. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for SEO poisoning or phishing campaigns. No scripts were extracted, and the document body was unreadable, limiting the analysis of the specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://niszczeniewaw.pl/userfiles/file/70427650176.pdf In PDF document text
    • http://tmtechvn.com/webroot/img/files/suronurixekotumegamoxuge.pdfIn PDF document text
    • https://www.focus.mu/wp-content/plugins/super-forms/uploads/php/files/d7992f54f6febdd2e3ce0ab5de7a46eb/13311922283.pdfIn PDF document text
    • https://semagro-msw.ru/pics/images/file/97853365758.pdfIn PDF document text
    • http://morakothotel.com/file_media/file_image/file/rijawazirokixaxefatena.pdfIn PDF document text
    • https://kolkatanagariksammelan.org/ckfinder/userfiles/files/xiwamapigidide.pdfIn PDF document text
    • http://aktasmatbaacilik.com/resimlerfiles/wipinatodonedofura.pdfIn PDF document text
    • http://drsrkbedcollege.com/ckeditor/ckfinder/userfiles/files/3834533177.pdfIn PDF document text
    • https://djennebeads.com/nbloom/fckuploads/file/62629659822.pdfIn PDF document text
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/816df9322dee64c3215b94ec65599059/wazososekope.pdfIn PDF document text
    • http://manavpublicschool.org/manav/userfiles/file/pufafixudezakafodufi.pdfIn PDF document text
    • http://kleinschadenexperte.de/userfiles/file/41618404178.pdfIn PDF document text
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fc36f9ebda---sexodew.pdfIn PDF document text
    • http://hangquangauto.com/files/tatiku.pdfIn PDF document text
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/tmp/wunepenununedazofegot.pdfIn PDF document text
    • http://www.naturhalles.fr/fckeditor/userfiles/file/mugutalafijavasorafaf.pdfIn PDF document text
    • http://commune-bourre.com/userfiles/file/fawekolerujameroz.pdfIn PDF document text
    • https://telechips.com/ckfinder/userfiles/files/19495875050.pdfIn PDF document text
    • https://alstar.uz/images/shared/file/dosikovoxu.pdfIn PDF document text
    • https://brune-schmuckwerk.de/ckfinder/userfiles/files/48904742483.pdfIn PDF document text
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/d1e6s692v3b439090qmqqhfu70/tasajilomekavituxaxujutas.pdfIn PDF document text
    • https://www.leasing.net.in/ckfinder/userfiles/files/88788917006.pdfIn PDF document text
    • http://aspbae.org/userfiles/file/fudijuxedugatiwalar.pdfIn PDF document text
    • https://nazrabilisim.com/calisma2/files/uploads/96989489591.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=english+sayings+pdfPDF 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_off0000d5c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5C9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000eddb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDDB 18228 bytes
SHA-256: 8186f36702c9b828ed5ce99e2670f81588761904f0c94d95bf2c15926fe7a905
font_02_sfnt_off00011d28.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D28 10424 bytes
SHA-256: 2a5eeda705ccc03a229f9c5ba065b1439d0f06f92616566f51d338372e7d0416