Malicious PDF — malware analysis report

Static analysis result for SHA-256 c2757a8b709bcae3…

MALICIOUS

PDF

70.8 KB Created: 2021-09-25 11:12:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 517b6f0829f9404f485a43daf6da85f4 SHA-1: caa9e6d75f196d295efe2aadf979097a1af86248 SHA-256: c2757a8b709bcae39c4308dd4bc8a585d974ec35d7260457fbf09722afe0d025
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier indicating maliciousness. The presence of numerous external URIs, many pointing to disposable domains and forming a link farm, strongly suggests a phishing or malware distribution attempt. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of malicious intent, likely to redirect users to harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://synerhu.ru/uplcv?utm_term=s4+screen+size PDF link annotation
    • http://exima.kr/userData/board/file/9799768955.pdfIn PDF document text
    • http://crosswaysrecruitment.com/userfiles/file/jemofenuvomajotet.pdfIn PDF document text
    • http://beauty214.com/uploads/files/202109031604467373.pdfIn PDF document text
    • http://farmaciafasolis.eu/userfiles/files/nodatedifevasifewivut.pdfIn PDF document text
    • http://elektromig.pl/userfiles/file/93914891606.pdfIn PDF document text
    • https://xn--b8qxb801j.tw/upload/files/bekigoxefuximexiro.pdfIn PDF document text
    • http://romovi.net/sgi_userfiles/userfiles/files/51358172187.pdfIn PDF document text
    • http://slsnn.ru/content/file/30368151891.pdfIn PDF document text
    • http://trungtamsangloc.vn/uploads/ck_upload/files/mozinidatus.pdfIn PDF document text
    • http://unicaconsultoriarh.com/images/files/buluzusariliruvuvu.pdfIn PDF document text
    • https://kalitelivideoizle.com/resimler/files/zujimiriris.pdfIn PDF document text
    • https://dondepodemosir.com/userfiles/file/lareraxiseromololoxawe.pdfIn PDF document text
    • https://ordermorestuff.com/cmsCart/upload/file/nusovibepuvikapurozaduma.pdfIn PDF document text
    • https://autosaloncenter.com/uploads/file/78003643112.pdfIn PDF document text
    • http://ajej.pretty-match.com/upload/files/37984183954.pdfIn PDF document text
    • https://mpksieradz.pl/upload/file/92586071809.pdfIn PDF document text
    • http://keemunblacktea.cn/uploads/file/011425022299.pdfIn PDF document text
    • http://www.biosafety.biz/ckfinder/userfiles/files/73994353100.pdfIn PDF document text
    • http://sisparts.pl/zdjecia/fck/file/kibejakogobamatumirozufu.pdfIn PDF document text
    • https://eventaipei.com/upload/files/8976361348.pdfIn PDF document text
    • http://meandnetworking.com/ckfinder/userfiles/files/jozexigapakesekalizugevop.pdfIn PDF document text
    • http://thementalhealthadvocates.org/files/userfiles/file/zuzagegapoxuzapupijowe.pdfIn PDF document text
    • https://www.lucaslobker.com/minor/ckfinder/userfiles/files/gubilowiveluvuxofes.pdfIn PDF document text
    • http://jcnjl.com/userfiles/files/92478934103.pdfIn PDF document text
    • http://tlumacz-bialystok.pl/pliki/file/nugunidixazifadoligonuw.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_off0000b45e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB45E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cc75.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC75 10008 bytes
SHA-256: 442df2e968bcb06b357d08395da033ca26c39e5f0fb04613f4589d9fb55a5fef
font_02_sfnt_off0000e2c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2C8 16788 bytes
SHA-256: eb7ec7e74fe8eb2db15cce4ac4d63a1359cb8894738477c003626c1f6374f04b