Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac3481d91beb8339…

MALICIOUS

PDF

76.0 KB Created: 2021-10-01 13:55:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 8d490e22a70f69341a29eceade834a83 SHA-1: 5fd9603aae13131c0d9cad141f7bdab16641d95b SHA-256: ac3481d91beb833908e0ea9662b781d37d793da77b40ab89b80285f31a4c15f6
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a large number of embedded URLs pointing to external sites, many of which are likely part of a link farm designed to redirect users. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests a phishing or malware distribution scheme. While no scripts were explicitly extracted, the nature of the embedded links and the overall structure point towards an attempt to lure users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9901

Heuristics 6

  • 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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • 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://inwebjor.ru/uplcv?utm_term=como+quitar+sonido+notificaciones+facebook+android PDF link annotation
    • https://birudongker.com/contents/files/99781744800.pdfIn PDF document text
    • http://szkolka-wiercioch.pl/files/file/72410006278.pdfIn PDF document text
    • http://transporteslaplata.com/imagenes_web/file/rezibudofawatosed.pdfIn PDF document text
    • http://ecohost.ru/pics/images/file/gapoweri.pdfIn PDF document text
    • http://sushiyaslo.com/uploads/files/39226379784.pdfIn PDF document text
    • http://dpkwi.org/userfiles/files/seriloxilotebinot.pdfIn PDF document text
    • http://sofia-es.tokyo/yamituki-n/uploads/files/metutikikikeb.pdfIn PDF document text
    • http://ambvetfanini.eu/userfiles/files/nakupalobi.pdfIn PDF document text
    • http://pass38.com/images/contentimages/files/sokeroposedabagojuva.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613642b1cee20---xamejepumigudelupaxe.pdfIn PDF document text
    • https://limpiezasinasel.com/userfiles/files/87733870091.pdfIn PDF document text
    • http://www.accessibilite-salle-eau.com/ckfinder/userfiles/files/66488848192.pdfIn PDF document text
    • http://bebsulmare.com/userfiles/files/wufovitinakefuzatowu.pdfIn PDF document text
    • http://holdemigny.fr/ckfinder/userfiles/files/zuwenaxumigukujugumapeb.pdfIn PDF document text
    • http://www.fishandcosolicitors.com/uploads/files/34573459090.pdfIn PDF document text
    • http://avandcie-energy.fr/ckfinder/userfiles/files/podurugatojadopu.pdfIn PDF document text
    • http://seatraderhk.com/userfiles/45739783828.pdfIn PDF document text
    • http://sushistoryus.com/uploads/files/xagazozuwuvawud.pdfIn PDF document text
    • http://ankaraeksioglu.com/resimler/files/69045891752.pdfIn PDF document text
    • http://mikol-styl.cz/userfiles/file/jugukineka.pdfIn PDF document text
    • http://sgrappresentanze.eu/userfiles/files/memuna.pdfIn PDF document text
    • http://geometramaurotozzi.it/userfiles/files/43837073789.pdfIn PDF document text
    • http://elementyzlaczne.pl/media/file/55710535377.pdfIn PDF document text
    • http://cobe-ing.it/userfiles/files/1796657332.pdfIn PDF document text
    • https://www.aukuras.org/ckfinder/userfiles/files/84784022363.pdfIn PDF document text
    • https://rowsontw.com/shopadmin/upload/files/84261959788.pdfIn PDF document text
    • http://bivalyracing.hu/files/file/toditeliw.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_off0000c073.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC073 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d885.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD885 18700 bytes
SHA-256: 15dd4d024a866b10ea028690c09f71de1778febbc344f9d6fe930c8192983f58
font_02_sfnt_off000107cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107CB 11100 bytes
SHA-256: 59b8ab263b69e2cbf1f56c37babbb6429a73a369b539e0c64d770a4a980efd0f