Malicious PDF — malware analysis report

Static analysis result for SHA-256 1737d9f43b2e3551…

MALICIOUS

PDF

85.9 KB Created: 2021-09-10 04:55:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: cb3f7f7f063b4cb3a39c148b2258ad1d SHA-1: 450fe02d15cb74af79963368f426c62db3305830 SHA-256: 1737d9f43b2e3551a16705a23c0bcb847a649c85a7fe18cd795e53632dd28560
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to disposable hosting and are part of a link farm, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of malicious activity, likely leading to a second-stage download or phishing page.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9848

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://crewmak.ru/uplcv?utm_term=get+app+name+android PDF link annotation
    • http://www.hangmandigital.com/files/file/6675228916.pdfIn PDF document text
    • http://npi-management.org/ressource/site-image/files/26282721093.pdfIn PDF document text
    • http://batiment-tunisie.com/userfiles/file/mekipabuxuxobepo.pdfIn PDF document text
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1613010a3a570a---36934430543.pdfIn PDF document text
    • https://lufty.cz/UserFiles/files/23035146205.pdfIn PDF document text
    • https://csam-villepinte.org/uploads/images/file/rurufibapiwirovoxulemij.pdfIn PDF document text
    • http://jlsxjy.com/right/UploadFile/file///2021090600163673499.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/1613361f5a468e---fisefufonifipos.pdfIn PDF document text
    • https://cambodiadriverservice.com/userfiles/file/maser.pdfIn PDF document text
    • https://taichielite.com/louis/taichi/ckfinder/userfiles/files/81450876625.pdfIn PDF document text
    • https://olgunbey.com/upload/ckfinder/files/difabukukegefez.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/92944301045.pdfIn PDF document text
    • http://bright-inter.com/file_media/file_image/file/7115802636.pdfIn PDF document text
    • http://apsencollege.org/test/fckeditor/file/ludigukuv.pdfIn PDF document text
    • http://dreambeauty.kr/upload/fckeditor/file/dimuliranawuvoruze.pdfIn PDF document text
    • http://somsit.com/ckfinder/userfiles/files/gevesexobebapik.pdfIn PDF document text
    • https://avukat.dnsaktif.net/upload/files/nanetoru.pdfIn PDF document text
    • http://xinshifm.com/userfiles/file/89006800717.pdfIn PDF document text
    • http://nuraski.pl/wsg/userfiles/28023304891.pdfIn PDF document text
    • http://beckydavidsonhomes.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139199245f2c---vonurixibazudegofomegiw.pdfIn PDF document text
    • https://frisch.ro/files/file/lekozimurifesi.pdfIn PDF document text
    • http://piqiso.ru/userfiles/file/kemikexawu.pdfIn PDF document text
    • http://cristal-in.fr/userfiles/file/86507635370.pdfIn PDF document text
    • http://retrievers.su/ckfinder/userfiles/files/xasatelesodudafo.pdfIn PDF document text
    • http://crosswaysrecruitment.com/userfiles/file/fodepunaj.pdfIn PDF document text
    • https://coherence.cz/userfiles/file/82868067984.pdfIn PDF document text
    • 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_off0000ede6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDE6 17508 bytes
SHA-256: 0de89b1fc19df3adf201bd99a0032cf0a8c60980738d95f8f299163107cfd16e
font_01_sfnt_off00011aef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AEF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013306.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13306 10376 bytes
SHA-256: ec9282857d098011ea729019ffab885edd3c673b4b8587814e0298eff0a9cd61