Malicious PDF — malware analysis report

Static analysis result for SHA-256 679fa08365ffd189…

MALICIOUS

PDF

82.0 KB Created: 2021-09-18 13:13:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 35b891c04e0c734ea57a92729f7bbdc1 SHA-1: 105c1e3bcb9b04f9345f3ee96adba4a7331f46cb SHA-256: 679fa08365ffd189a8664f98cb8bf50d52f45eb19b221cf41c40e8d741cb6a37
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, suggesting a link farm designed to distribute malware. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution. No scripts were extracted, but the presence of external links and the nature of the heuristics point towards a phishing or downloader attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://ketchas.ru/uplcv?utm_term=free+download+super+vpn+apk PDF link annotation
    • http://shinaval.ru/userfiles/file/16065549931.pdfIn PDF document text
    • http://em-mould.com/ckfinder/userfiles/files/98829084903.pdfIn PDF document text
    • https://bahia-group.com/ckfinder/userfiles/files/lerugosuwemab.pdfIn PDF document text
    • http://citadelcaralarms.com/userfiles/file/kasugut.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/1613ebb52296e1---7961064325.pdfIn PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141729ac86ab---7278967529.pdfIn PDF document text
    • http://tomaszfilipczak.pl/userfiles/file/gekibiwatu.pdfIn PDF document text
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/l3umrt2ikn8e8chidb064r2nkt/39501900601.pdfIn PDF document text
    • http://sushistoryus.com/uploads/files/11230418041.pdfIn PDF document text
    • https://apra.pl/files/file/17588317840.pdfIn PDF document text
    • http://revucue.com/ckfinder/userfiles/files/fadijoxafibomuxinijaxev.pdfIn PDF document text
    • http://hotelborgodeipoeti.com/userfiles/files/nibuniwagolofodifimalos.pdfIn PDF document text
    • https://shevtsov-art.com/uploads/files/tivula.pdfIn PDF document text
    • https://laptopserwis.com/app/webroot/media/files/14153102748.pdfIn PDF document text
    • http://clinicaveterinariaalbese.eu/userfiles/files/18550706871.pdfIn PDF document text
    • http://i-physiology.ru/upload/mexitudiladigazawov.pdfIn PDF document text
    • https://infrastone.com/userfiles/files/77875042516.pdfIn PDF document text
    • http://tries.cz/media/images/upload/file/62958742967.pdfIn PDF document text
    • https://marathonlaval.com/userfiles/files/75931156145.pdfIn PDF document text
    • http://somkuthyoptika.hu/editor_up/35440101906.pdfIn PDF document text
    • http://fincasotilloviejo.es/files/sotillo/_repo/file/jepowenaveverelixaruve.pdfIn PDF document text
    • http://studioscoponi.eu/userfiles/files/38877768740.pdfIn PDF document text
    • http://martonelektro.hu/files/file/dodedupurefamemix.pdfIn PDF document text
    • http://profitoolinfo.ru/ckfinder/userfiles/files/zepivugirinegalap.pdfIn PDF document text
    • http://gintaras.cz/userfiles/file/17720946600.pdfIn PDF document text
    • http://www.rlktechniek.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16131c646b5217---3223070847.pdfIn PDF document text
    • https://topclassgardening.nl/images/file/90310791909.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_off0000decc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDECC 16992 bytes
SHA-256: 3515b7baf95d47577f7a956afaf960cc63e374e5fcadcf0f0f55d9440ae06ac2
font_01_sfnt_off00010a3a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A3A 10516 bytes
SHA-256: 2742af4907fc90127bfc0cf6fd658ef349600c4d965f5038e1c14ea2d92ebbde
font_02_sfnt_off00012255.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12255 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1