Malicious PDF — malware analysis report

Static analysis result for SHA-256 da3b8d281c33f1b3…

MALICIOUS

PDF

90.2 KB Created: 2021-09-08 16:26:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: fb290b44aaf23e5cc06343bbaaed68ac SHA-1: 79af96160c5609423b7eb88306948bd40e68db21 SHA-256: da3b8d281c33f1b361ed409c4151de4afed5b7fb7111e05c5387fb6765d5cd2a
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous URLs, many of which are hosted on disposable domains or compromised CMS upload directories, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://crysiq.ru/uplcv?utm_term=variabilidad+genetica+definicion+pdf PDF link annotation
    • http://www.520amis.com/upload/files/52080488111.pdfIn PDF document text
    • http://kiapelhrimov.cz/UserFiles/File/witizemejemuwa.pdfIn PDF document text
    • http://getrade.net/uploadfiles/file/52689579399.pdfIn PDF document text
    • http://rutka.pl/media/upload/files/ea2812c62fa58e5e29acc514e0b0e8d6.pdfIn PDF document text
    • http://softwaretesting.kr/club/data/userfiles/file/20210901225428.pdfIn PDF document text
    • http://jjsgreatescape.com/uploaded_files/userfiles/files/witurukusakajugodotogo.pdfIn PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/161322921b65f0---morel.pdfIn PDF document text
    • https://parkettworld.com/upload/files/jopivamatevexefoneze.pdfIn PDF document text
    • http://aitrans.cn/UploadFile/file/F1202109081930397030.pdfIn PDF document text
    • https://hiperaktivite.info/userfiles/files/zamonidam.pdfIn PDF document text
    • http://aardbeienfeesten.nl/uploadimages/files/81971827289.pdfIn PDF document text
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/b08ff9985abc84ec76e7881ea880b4c2/dowimususugu.pdfIn PDF document text
    • https://rallstarawards.us/nbloom/fckuploads/file/77992545415.pdfIn PDF document text
    • https://hkbca.org/UploadFiles/file/20210903043804170.pdfIn PDF document text
    • http://montazenabytkupraha.cz/files/file/xefemefufivug.pdfIn PDF document text
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136d565aba37---78845775650.pdfIn PDF document text
    • http://toroisg.com/public/images/files/35264859799.pdfIn PDF document text
    • http://akiyastyle.com/app/webroot/js/ckfinder/userfiles/files/26357516972.pdfIn PDF document text
    • http://amongelite.com/ci/userfiles/files/86234821946.pdfIn PDF document text
    • http://topbondtape.com/uploadss/file/10461788987.pdfIn PDF document text
    • https://novahealthclinic.ca/userfiles/file/81908816251.pdfIn PDF document text
    • http://metabolit.ru/files/file/vovegovebuzumubizizanim.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_off0000f95c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF95C 10736 bytes
SHA-256: 656372edd586845782b08ff3327271c68f7d22f572e6d6749ad42b8f3bf866e3
font_01_sfnt_off000111ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111AE 19328 bytes
SHA-256: db60c5d9b7d800baa5572f0ae3f754c723d7b1e83829cbfbcb577236e2476d88
font_02_sfnt_off000142df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x142DF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1