Malicious PDF — malware analysis report

Static analysis result for SHA-256 c913e41efd39dc30…

MALICIOUS

PDF

87.9 KB Created: 2021-09-12 05:15:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: b12d91f5851a4342bd84d2d260d9e456 SHA-1: 2a8adc703d6d25164d755e7caca3d8dac22fbad4 SHA-256: c913e41efd39dc30d659b49c256674376c2aaedc1978aef4dc62b0b0336cd1e2
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically identified as a phishing trojan. It contains numerous embedded URLs, many of which point to disposable domains and are structured as a link farm, a common tactic for phishing or distributing further malware. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests this malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://nutranghongngoc.com/media/ftp/file/napobosufis.pdf In PDF document text
    • https://generalaudit.pl/eurostyl/photos/file/digevi.pdfIn PDF document text
    • http://18554080.com/userfiles/file/3010454136.pdfIn PDF document text
    • http://biosystech.com/pdsFck/file/kefofusaxumalolop.pdfIn PDF document text
    • https://hanurichurch.org/ckfinder/userfiles/files/80359007048.pdfIn PDF document text
    • https://www.penyembuhanholistikreiki.com/wp-content/plugins/formcraft/file-upload/server/content/files/161311ed85df6c---samemegovu.pdfIn PDF document text
    • http://cobe-ing.it/userfiles/files/84274430972.pdfIn PDF document text
    • https://nieruchomosciprzetargi.pl/files/file/99838052067.pdfIn PDF document text
    • http://stfurnimart.com/file_media/file_image/file/12837517678.pdfIn PDF document text
    • http://mlead.net/images/e/file/7192347239.pdfIn PDF document text
    • https://zmiz.hr/userfiles/file/ketomijive.pdfIn PDF document text
    • http://canadianartistic.com/userfiles/file/27951993159.pdfIn PDF document text
    • https://hotelharmika.com/assets/userfiles/files/62442249239.pdfIn PDF document text
    • http://restokrat.info/userfiles/file/zeketozipuzobiz.pdfIn PDF document text
    • http://zuszdounky.cz/files/51628218943.pdfIn PDF document text
    • http://sourceandsecure.com/uploads/userfiles/file/14962325960.pdfIn PDF document text
    • http://www.introspekta.si/ckfinder/ckeditor_uploaded_files/files/gajewu.pdfIn PDF document text
    • http://studiopiergentili.it/userfiles/files/5993307830.pdfIn PDF document text
    • http://impactpluslearning.com/ckfinder/userfiles/files/favipafolamaxu.pdfIn PDF document text
    • http://amsaneeraus.fi/userfiles/files/bazijexopujofoxeze.pdfIn PDF document text
    • http://tpdw.pl/userfiles/file/46042056824.pdfIn PDF document text
    • http://la-roofers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613897b35768a---47726881106.pdfIn PDF document text
    • http://abwalabamaave.com/uploads/files/5179564237.pdfIn PDF document text
    • http://mamam.by/upload/File/file/36052298373.pdfIn PDF document text
    • http://bjerkelunden.org/content/files/userfiles/file///tapomefakameji.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=jump+scare+maze+game+unblockedPDF 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_off0000eefc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEFC 18900 bytes
SHA-256: 0ca3c481590d96a3408dc90daa24f9b41aaa9e5c720d295e0aaaa029e9149d2a
font_01_sfnt_off0001202e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1202E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013845.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13845 11048 bytes
SHA-256: f7b238c579061df5eb52159a4130db288ba8977d1bed9c44934287e642164db4