Malicious PDF — malware analysis report

Static analysis result for SHA-256 3fd837875cd07db5…

MALICIOUS

PDF

83.0 KB Created: 2021-07-18 16:08:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: a377874bff6c9003d2a590d51ed447c0 SHA-1: 3f56060fcc5021c2e6ef5c3c5ff9482300248fcd SHA-256: 3fd837875cd07db5a351693595d87489689c78e1e85a572b88e4b6456881423a
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The file contains numerous links to external websites, many of which are hosted on compromised CMS platforms or appear to be part of a link farm, suggesting an attempt to direct users to malicious content. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond the heuristic findings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://tunglamgarden.com/images/fck/file/burunolopizupateduwefon.pdf In PDF document text
    • https://mannerfeltdesignteam.se/ckfinder/userfiles/files/senojisodizaposezomujigo.pdfIn PDF document text
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16088c0429619c---xamajaw.pdfIn PDF document text
    • http://pokemom2.com/uploads/files/64096329546.pdfIn PDF document text
    • http://asesorialuishervas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c5393323233---kikanikuvulipugowim.pdfIn PDF document text
    • http://delawaretravelmedicine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b46a529eff---kejaxevujudirerewosepu.pdfIn PDF document text
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a7420b292d---beneposuxibu.pdfIn PDF document text
    • https://segurosjdd.com/wp-content/plugins/super-forms/uploads/php/files/usq9lal2ipii4itkp11qh3oq45/20659717381.pdfIn PDF document text
    • http://cornucopiafrederick.com/uploads/files/wedefokositedazekopor.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/q0m4rrfhd96crat7heefb9vdt3/sewotatafuluzusositeje.pdfIn PDF document text
    • http://bearings-home.com/userfiles/file/gejuparozivewu.pdfIn PDF document text
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/adijt30oqjktj1olstptb2ruff/84062248567.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1608b6a14e7374---44427853493.pdfIn PDF document text
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b0359787d39---kuzufakogosipodokazosata.pdfIn PDF document text
    • http://tvoirostov.ru/ckfinder/userfiles/files/65243730985.pdfIn PDF document text
    • https://leicht-spb.ru/wp-content/plugins/super-forms/uploads/php/files/08ba16c74a7cb53771b00db04185e71c/lapiw.pdfIn PDF document text
    • https://samarpanbharat.org/trila/userfiles/file/makusezu.pdfIn PDF document text
    • http://inspiredindianfoundation.org/uploads/60079888908.pdfIn PDF document text
    • http://www.putnamtaxi.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607fee4fe07a0---35317985973.pdfIn PDF document text
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a81afe040bd---81424233623.pdfIn PDF document text
    • http://hacoauto.vn/upload/files/96068007777.pdfIn PDF document text
    • http://www.ibadirect.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fff5106ee8---gorazejojuni.pdfIn PDF document text
    • http://bertoniamministrazione.it/bertoni/public/file/wumikotijisukekamuwebabaz.pdfIn PDF document text
    • https://law.myvzl.com/wp-content/plugins/super-forms/uploads/php/files/mcpitiorvv73fu970na9b8spmd/69425751173.pdfIn PDF document text
    • https://weddingitaly.jp/images/file/kabavurevo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=god+does+not+give+us+a+spirit+of+fear+kjvPDF 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_off0000e3bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3BC 11052 bytes
SHA-256: 452cb07630c12e2f2bb12b9c4120f5cdc542446b57f4ec91c5afee7b600318bc
font_01_sfnt_off0000fd76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD76 16056 bytes
SHA-256: 34f2a6cf357567e96c2abd7808f2e5f4ca12add4bb8814f1d50b544b6dbd24aa
font_02_sfnt_off00012675.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12675 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1