Malicious PDF — malware analysis report

Static analysis result for SHA-256 811cac4078c78546…

MALICIOUS

PDF

77.9 KB Created: 2021-09-24 10:05:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 52ce6726724498e045d930dbb270dd39 SHA-1: 85034f6cd9603c0054320634f149009a1edf6b03 SHA-256: 811cac4078c78546c87636c86a232c7c56e5ad7fa521935f4687fd1337531232
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, specifically flagged as 'Pdf.Phishing.Trojan'. Static analysis revealed it functions as a link farm, containing numerous URLs pointing to various domains. Several of these URLs lead to compromised CMS upload directories or disposable hosting, indicating a likely intent to host phishing content or distribute further malware. The presence of multiple external URIs and the 'Malicious Link' heuristic strongly support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://doorsatyrau.com/ckfinder/userfiles/files/vubuxuderasiteluwaf.pdf In PDF document text
    • http://www.bufolari.com/public/immagini/file/23261193443.pdfIn PDF document text
    • https://bepxuyenviet.com/upload/files/nusomefurelole.pdfIn PDF document text
    • https://arslanemlak.com/E/file/In PDF document text
    • https://przyklejki.pl/userfiles/numupirudoxadiz.pdfIn PDF document text
    • https://jagominum.com/contents/files/texusukorijopesuzesux.pdfIn PDF document text
    • http://baharemadinah.com/wp-content/plugins/formcraft/file-upload/server/content/files/161428d0c2ed3d---52842947177.pdfIn PDF document text
    • http://ifaistos.reality.gr/~triantaf/images/file/mebodibapanogozisolubede.pdfIn PDF document text
    • http://www.farmaciavictoriayjmleon.com/userfiles/files/tigumizumebirogivezukow.pdfIn PDF document text
    • https://floridainvestment.cz/files/file/58271964893.pdfIn PDF document text
    • http://erulingua.hu/uploads/content_files/files/gemokibafo.pdfIn PDF document text
    • https://anukulagrotech.com/userfiles/file/selosi.pdfIn PDF document text
    • https://maintogelonline2.bet/contents/files/piluwipa.pdfIn PDF document text
    • http://newabel.com/ckfinder/userfiles/files/58876358504.pdfIn PDF document text
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138196cf0a9f---reloko.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136856326d78---jefejikigu.pdfIn PDF document text
    • https://artistaone.co/userfiles/files/99669821312.pdfIn PDF document text
    • http://servis-hradec.cz/files/file/ziveralipobafekunesatuxi.pdfIn PDF document text
    • http://all-paca.com/ckeditor/ckfinder/core/connector/php/uploads/files/28953212739.pdfIn PDF document text
    • https://kalimati.in/userfiles/file/vidafor.pdfIn PDF document text
    • http://simpelms.nl/userfiles/files/nonikawobugajole.pdfIn PDF document text
    • http://kepco-group.com/uploaded_files/userfiles/files/3107654531.pdfIn PDF document text
    • https://savitravel.ro/ckfinder/userfiles/files/pibinefafivanume.pdfIn PDF document text
    • https://promoform.coreform.it/uploads/file/59628259437.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=the+best+free+games+frivPDF 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_off0000cce2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCE2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e4f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4F9 10560 bytes
SHA-256: 3b9853160efad16f8f9e6166d787146b2eea74751ba30d0e4e0ed6c53ec5270a
font_02_sfnt_off0000fd1d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD1D 17316 bytes
SHA-256: ed5a18c74c19b6f4f629aca535e2efcd3f130c29da6ab04c6e4d8ab16d1e5e02