Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b855f4cfd8ab33b…

MALICIOUS

PDF

87.9 KB Created: 2021-09-11 14:45:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 4a064b47bbb043fec8acf6583aee3166 SHA-1: 152c8a25bc841d0afa3f9f62141a535f664b1b1a SHA-256: 4b855f4cfd8ab33b5ad419005a874ff7d0bd4625d881c4cd78726a108402d8e1
126 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as a phishing trojan and by an ML classifier as malicious. Heuristics indicate it functions as a link farm, containing numerous links to other PDF files hosted on various domains. This suggests an attempt to manipulate search engine results or distribute additional malicious content through a chain of documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9922

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://terminarz.online/kosmetyczka/krakow/files/48955359670.pdf In PDF document text
    • http://www.catedralirodahaz.hu/data/editorfile/tosafedonijudafo.pdfIn PDF document text
    • https://spitalmoldovanoua.ro/ckfinder/userfiles/files/libedasorutojukaje.pdfIn PDF document text
    • http://teplolux72.ru/upload/file/9916146326.pdfIn PDF document text
    • http://cpviettin.com/upload/files/kosij.pdfIn PDF document text
    • http://alpes-de-haute-provence.proximeo.com/ckfinder/userfiles/files/xuzisas.pdfIn PDF document text
    • http://inphilong.com/upload/files/noxelusifovijajegeseke.pdfIn PDF document text
    • http://tizianaiberti.it/userfiles/files/58462662744.pdfIn PDF document text
    • http://steelbo.com/uploads/admins/u0/files/20210908124741.pdfIn PDF document text
    • http://psychanalyste-gard.fr/ckfinder/userfiles/files/91119065671.pdfIn PDF document text
    • http://foto-recepty.sk/images/fotky/22045528032.pdfIn PDF document text
    • http://business-plan-capalpha.eu/mbp/upload/images/images/upload/ckfinder/gulabufamonipaza.pdfIn PDF document text
    • http://bisenzia.it/userfiles/files/kebivozolub.pdfIn PDF document text
    • http://vegman-kzn.com/ckfinder/userfiles/files/zepoxuxanukujotoli.pdfIn PDF document text
    • http://ruresept.ru/files/file/jerenufibibetaj.pdfIn PDF document text
    • http://nicolalazzarotto.com/userfiles/files/rabumamenofaxojavi.pdfIn PDF document text
    • https://blnk.eu/userfiles/files/32683567944.pdfIn PDF document text
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613164290f5af---13739674787.pdfIn PDF document text
    • https://ceccarbotosani.ro/userfiles/file/861013000.pdfIn PDF document text
    • https://carparts-fixture.com/file/file/15310330895.pdfIn PDF document text
    • http://dulichtantai.com/files/uploaded/files/zisuju.pdfIn PDF document text
    • http://pinxedien.net/upload/files/18086930438.pdfIn PDF document text
    • http://minhphucvietnam.com/uploads/userfiles/file/35772835900.pdfIn PDF document text
    • https://maggievanostrand.com/uploads/media/file/84438868943.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=lethal+weapon+movie+watch+freePDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000db17.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB17 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f32e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF32E 10688 bytes
SHA-256: 62e1627fa82e2104007caab9363391fea996e345227db062a80e376242be8e15
font_02_sfnt_off00010b80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B80 16632 bytes
SHA-256: e896d0c9c6509c93731645541c0836c845742b74f7fde2e8ff5e94baacc6a6a0
font_03_sfnt_off0001230d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1230D 17952 bytes
SHA-256: 14679f22f1ce6b99ac782edd65ccdfccd0b87ba078c527453c88dc1a5573f5bf