Malicious PDF — malware analysis report

Static analysis result for SHA-256 d4b9a3185db782d4…

MALICIOUS

PDF

76.3 KB Created: 2021-09-10 02:12:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 4cfd82596dfa5fa72ad665cd1ac00978 SHA-1: 52942a09532a0294c0a62585f440a86a12657260 SHA-256: d4b9a3185db782d41f8908e7d758d7b7f5e14c72f7f1b6350d710da6819aab44
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URIs and is identified as a link farm on disposable hosting, suggesting a phishing or malware distribution scheme. Although no scripts were explicitly extracted, the PDF structure and embedded URLs point towards an attack pattern involving redirection to potentially harmful external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://garglob.ru/uplcv?utm_term=environmental+degradation+meaning PDF link annotation
    • http://lachina.cn/upload/file/174212229.pdfIn PDF document text
    • http://eatatrudy.com/uploads/files/posoxi.pdfIn PDF document text
    • http://protectakoteasia.com/ckfinder/userfiles/files/lugafadojopabovewafigakur.pdfIn PDF document text
    • https://edouardweil.com/userfiles/file/17478826664.pdfIn PDF document text
    • https://loppisidjupdalen.se/images/uploaded/file/90081570534.pdfIn PDF document text
    • http://avtrak.ru/ckfinder/userfiles/files/wedimelotinidesivurivo.pdfIn PDF document text
    • http://kindergartenhelden.at/upload/file/14309063172.pdfIn PDF document text
    • http://redemaisfarma.com/userfiles/file/25535952794.pdfIn PDF document text
    • http://ambvetbrashersclavoghisu.eu/userfiles/files/42624314570.pdfIn PDF document text
    • http://kramor.bg/userfiles/file/60539133258.pdfIn PDF document text
    • https://fallsplat.se/bildbank/file/losizinesi.pdfIn PDF document text
    • http://goldmustang.com/files/files/likijavigunewino.pdfIn PDF document text
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1612eb4a789a2c---92810910184.pdfIn PDF document text
    • http://www.sanjuktabanerjee.com/fckimages/file/masubigon.pdfIn PDF document text
    • https://www.caissedesecolesdu5eme.fr/backoffice/ckfinder/userfiles/files/46930639679.pdfIn PDF document text
    • https://heatingboiler.ca/fck_upload/file/81998507218.pdfIn PDF document text
    • http://anshan56.cn/userfiles/file/16310435021897129383.pdfIn PDF document text
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137e368cca5b---51181995746.pdfIn PDF document text
    • https://gfwofficial.com/ck_imgs/files/pekazoluvimal.pdfIn PDF document text
    • http://screen.by/images/file/winajapitarewakigajubonat.pdfIn PDF document text
    • http://vako.vn/app/webroot/uploads/files/sarupa.pdfIn PDF document text
    • http://tjtvina.com/Upload/files/88731687243.pdfIn PDF document text
    • https://catbasailing.com/upload/fck/file/tekuwuvo.pdfIn PDF document text
    • http://ct-tci.com/cttax/userfiles/files/podawebidapudazuvofobaxix.pdfIn PDF document text
    • http://www.centrosanmarco.eu/img/news/files/tojodamimazo.pdfIn PDF document text
    • http://nattukoottam.com/userfiles/file/memevofipokomabinezaso.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_off0000c810.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC810 10472 bytes
SHA-256: 83bf52b2a735e803109eec1b7d6f9eb76fe97dfaa7ce9a1f582dd996080fecce
font_01_sfnt_off0000df94.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF94 17072 bytes
SHA-256: b6cb2430010c2683915aa953c22f6b45d781910694a404c9bd25286e405caf16
font_02_sfnt_off00010b93.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B93 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1