Malicious PDF — malware analysis report

Static analysis result for SHA-256 a33e83b36737a8e8…

MALICIOUS

PDF

79.4 KB Created: 2021-09-03 19:59:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: bb399417e2dd4cd77bb244865212b9b4 SHA-1: 0e1084eb54ec1e6ad200f23d052c960432a5b267 SHA-256: a33e83b36737a8e8361f079a164a13061be39ae1ef02e26fb5e1ea3cebe99267
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs that point to other PDF files hosted on compromised websites, indicating a link farm or redirection scheme. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. While no scripts were explicitly extracted, the nature of the embedded URLs and the heuristic firings point towards a phishing or malware distribution campaign.

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://peknanevesta.sk/media/file/jijisunatanokopopor.pdf In PDF document text
    • https://299-45.com/CKEdit/upload/files/judibemumaxaroseme.pdfIn PDF document text
    • https://thetitangroup.ca/wp-content/plugins/super-forms/uploads/php/files/f682a54bb16af8a8224788eafc2edf03/40188400268.pdfIn PDF document text
    • http://aep-tc.com/cache/fck_files/file/fufigovalul.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/160b2eac8916c8---jepemuweribaxovasalesi.pdfIn PDF document text
    • http://dui-antidote.com/images/userfiles/file/vidavov.pdfIn PDF document text
    • http://call.ae/wp-content/plugins/formcraft/file-upload/server/content/files/16075d16410836---pikomiwife.pdfIn PDF document text
    • https://esportenerd.com/app/webroot/ckfinder/userfiles/files/gexagesoxokarivezilifu.pdfIn PDF document text
    • https://web-sila.ru/wp-content/plugins/super-forms/uploads/php/files/46aca407cc9ecb73642596fcd31cd7b5/duvibawoxaseketosi.pdfIn PDF document text
    • http://hondasushi.com/uploads/files/jaxuxed.pdfIn PDF document text
    • http://cp-tournament.org/ckfinder/userfiles/files/renamudosux.pdfIn PDF document text
    • https://alohasafaris.com/files/takepolavoginibojir.pdfIn PDF document text
    • http://lyzph.com/userfiles/file/Fl202107300423229475.pdfIn PDF document text
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a8da0fbab1a---mavofekiteginalenobafe.pdfIn PDF document text
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077ca9b419c2---41336936845.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/p3lj4vuvm9723uv9sc91jn2r84/wapawuwafidago.pdfIn PDF document text
    • http://streathamtaxi.com/survey/userfiles/files/68681499597.pdfIn PDF document text
    • https://ccichn.vn/data/upload/file/zezufogomuloj.pdfIn PDF document text
    • http://beccaro.it/userfiles/files/33344192341.pdfIn PDF document text
    • http://www.radioemka.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072f7e37941a---94806815922.pdfIn PDF document text
    • http://studiogiamberardino.it/userfiles/files/bakixaxibudezujovutup.pdfIn PDF document text
    • http://scissortailfarms.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610fa90c8c4d8---3873814006.pdfIn PDF document text
    • http://chinhsuasolieu.com/media/files/vufagelos.pdfIn PDF document text
    • http://nail-free.com/ckfinder/userfiles/files/vorokilinipuzivilewarad.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=finance+manager+duties+and+responsibilities+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_off0000d2b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2B2 11180 bytes
SHA-256: 9162087b6d67d6adaf8b8dae283d792cd16cb6b9e11cf7f284bf11e05868aa4b
font_01_sfnt_off0000ec5b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC5B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001046d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1046D 16996 bytes
SHA-256: 5dcbf5d4358a22273b5c5680877e7635ee2bc8cb9d3246907f4cc6dcd5b6b208