Malicious PDF — malware analysis report

Static analysis result for SHA-256 33cf9d1ee9d6f575…

MALICIOUS

PDF

74.5 KB Created: 2021-09-03 05:30:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: cc2c3b907f55e450cc0aa80f82b2a563 SHA-1: 72d844b78e99687445222931bf2ed51114c21624 SHA-256: 33cf9d1ee9d6f57528e8258ce68fe05a1dcad13185d1f4dfe381df70ab5bd5ef
204 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains embedded JavaScript and links to algorithmically-generated URLs, indicating an attempt to redirect the user to malicious sites. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or distributing further malware. The presence of JavaScript points to its use in executing malicious actions within the PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

Heuristics 8

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/161232883dcbf0---66714407302.pdf
    • https://yapluka-services.fr/userfiles/file/nedanidud.pdf
    • http://paolacaone.eu/userfiles/files/zifajananuzupebowuf.pdf
    • http://cameralehiep.com/hinhanh_fckeditor/file/13012481275.pdf
    • https://bda.ch/ckfinder/userfiles/files/leterefifo.pdf
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/0e57a1221c1b17d1281447b17f274ecf/33883827586.pdf
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c05a474d345---83555347217.pdf
    • http://yulintimber.cn/d/files/vetinudi.pdf
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a8198e3badb---93516949653.pdf
    • http://haisushitogo.com/uploads/files/35278062715.pdf
    • https://mimpishio2bet.com/contents//files/91854581380.pdf
    • https://aslimitada.com/userfiles/file/zupilemepovi.pdf
    • http://altus.pl/userfiles/file/72311848161.pdf
    • https://nothingbutsafetyglasses.com/userfiles/file/sobiwufolarepud.pdf
    • http://csim.jp/ckeditor/uploads/files/zawoje.pdf
    • https://habibitours.com/ckfinder/userfiles/files/63817137263.pdf
    • http://pomocnaukowa.net/Upload/file/badivotu.pdf
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/16086a3224b2dd---kakon.pdf
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc668b11c2---21130569622.pdf
    • https://cottonweb.net/userfiles/file/menebivamenefiga.pdf
    • https://internationallanguagenavigators.com/media/wexivo.pdf
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f2d701ecb6---74058911659.pdf
    • https://robertmatzuzi-massagetherapist.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160b804db3741a---zikotelatumuzo.pdf
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16099ceead65be---25830512522.pdf
    • https://www.agro-zavod.ru/app/webroot/js/ckfinder/userfiles/files/xukafazumefokazuzejuwosex.pdf
    • http://montpellier-businessplan.com/mbp/upload/images/images/upload/ckfinder/51268366577.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=bmw+x3+automatic+or+manual
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c02e.bin
903bd4278700148bf447fe662766c68f85ffe9307edd1d90ec6e1e8968f68234
pdf-font-stream PDF embedded font (sfnt) at offset 0xC02E 17000 bytes
font_01_sfnt_off0000ebfc.bin
578acbb1160e2b8a8c9eb12d98887f9cc2bdc0b9a455d9c920b53d3a6a677215
pdf-font-stream PDF embedded font (sfnt) at offset 0xEBFC 10604 bytes
font_02_sfnt_off0001044f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1044F 16792 bytes