Malicious PDF — malware analysis report

Static analysis result for SHA-256 a103139fe6d555d6…

MALICIOUS

PDF

77.8 KB Created: 2021-09-21 18:05:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 314bc3d0bf2b39706005fb67fa380af9 SHA-1: 1a0e5dbd0e3c687cf46811eb32142d264b637ad6 SHA-256: a103139fe6d555d607a977f6d611dc5f4b228f9e7cb397dbf71db0bcd30c9638
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, with a significant heuristic firing indicating it's a link farm on disposable hosting. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware delivery. While no scripts were directly extracted, the structure and URL distribution point towards a campaign to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

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 http://discus-rus.ru/upl/file/zusimamaw.pdf In PDF document text
    • http://medigroupvn.com/upload/files/78375831884.pdfIn PDF document text
    • http://ysmenmidwestindia.org/uploads/userfiles/file/file/8005067555.pdfIn PDF document text
    • http://sedaciesupravy.sk/media/file/zobozeloxisubuf.pdfIn PDF document text
    • http://gamax-moto.cz/data/dokumenty/22459434734.pdfIn PDF document text
    • http://xn--90aoaidn.xn--p1ai/ckfinder/userfiles/files/dilumasudapolalimujemag.pdfIn PDF document text
    • http://www.accessibilite-salle-eau.com/ckfinder/userfiles/files/xufibubofubiwawasifiximu.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/a2a7mv775duouvopee3kq77tb4/masumiwari.pdfIn PDF document text
    • http://cw-cut.com/uploads/file/kozilivunamomewofazedom.pdfIn PDF document text
    • http://dentalcenterstudio.it/userfiles/files/79606383442.pdfIn PDF document text
    • https://needlugs.com/userfiles/files/buvazejewa.pdfIn PDF document text
    • https://lidiyageorgieva.com/ckfinder/userfiles/files/vaselepazut.pdfIn PDF document text
    • http://giasuthanhdat.vn/Images_upload/files/9813719443.pdfIn PDF document text
    • http://navrattan.co/userfiles/file/suxajixawidijuvoxo.pdfIn PDF document text
    • http://humidorio.de/ckfinder/userfiles/files/tanofavu.pdfIn PDF document text
    • http://supair-lux.hu/ckfinder/userfiles/files/8041930927.pdfIn PDF document text
    • https://windsbs.biz/files/file/wuxuriwaladibegevasa.pdfIn PDF document text
    • https://mariapolis.es/ckfinder/userfiles/files/93537035652.pdfIn PDF document text
    • https://stehovani-ostrava.cz/static_pages_files/file/32694305585.pdfIn PDF document text
    • http://pedraferro.com/files/files/98179818069.pdfIn PDF document text
    • https://responsible-tourism-alliance.com/content_file/files/8430238230.pdfIn PDF document text
    • https://karapinler.com/calisma2/files/uploads/duvipipitagugusikedazipew.pdfIn PDF document text
    • http://kxqcgs.com/filespath/files/20210916105851.pdfIn PDF document text
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16137c9a76e94b---8647018246.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=no+play+store+on+chromebookPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b4d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB4D1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cce2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCE2 17800 bytes
SHA-256: 3c33cce3dd2e87b970fe0c64fb261ac5e1942a6608bcf5bca2c20945b4b0f058
font_02_sfnt_off0000e87c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE87C 10872 bytes
SHA-256: 9d2723de28caab37a7728976a393b787165b588b6aeff37d1d04c12e48ee3fd8
font_03_sfnt_off0001014c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1014C 15476 bytes
SHA-256: 19f448746d46ee3b2e755d4ab438fa16b5458d24d9f2c50ec1b71f313833f566