Malicious PDF — malware analysis report

Static analysis result for SHA-256 235f0a0f91aca772…

MALICIOUS

PDF

80.4 KB Created: 2021-09-03 08:04:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: be258364996f46d535d6917f574c68a0 SHA-1: 85d921d20eafdd37838d6b954558dd46e07cf909 SHA-256: 235f0a0f91aca772db18a35204081446bd1b0b6bad7970ae96c905053f03bc34
222 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by multiple heuristics as malicious, including repeated payload links and a link farm pointing to compromised CMS uploads. The presence of numerous embedded URLs, many leading to potentially malicious content, suggests an attempt to redirect the user to a malicious site or download a payload. The ML classifier also strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

Heuristics 7

  • Invisible/repeated PDF links deliver payload file critical PDF_REPEATED_PAYLOAD_LINK_LURE
    PDF uses invisible link annotations and points to a direct payload download. Repeated invisible links or lure-like payload names such as document/unlock/verify archives match malware-delivery PDF carriers where the page is only a prompt and the real payload is fetched from the linked URL.
  • 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 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://matstravel.ru/userfiles/file/59374764788.pdf
    • http://pmteventures.com/clients/5/57/576e8e71b788aac95a268099fab76a3d/File/vomaponogazadakiledelide.pdf
    • http://casaledellasignora.it/userfiles/files/jizogabisanipopekef.pdf
    • https://inchiriereelicoptere.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608c97e1dbf84---wewerubojeko.pdf
    • https://mindweave.co.uk/wp-content/plugins/super-forms/uploads/php/files/am7urv4gnvie4n9fea8ltbrasa/38534695749.pdf
    • https://ntct.dz/ckfinder/userfiles/files/pariferimorapan.pdf
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/1606d5c0ba1eb8---gujonudazomerexobeb.pdf
    • http://herodumpsterrental.com/wp-content/plugins/super-forms/uploads/php/files/abbd75c8b822abdd5b74f2ab8a650df7/24180721320.pdf
    • http://15881588.com/ckupload/files/dojubepesulugufe.pdf
    • http://morgancountyoh.com/userimages/16038261323.pdf
    • https://regeneracion-capilar.com/wp-content/plugins/super-forms/uploads/php/files/762f52bed07ebc543ce460042a9c4df0/sufezugawu.pdf
    • https://x-leather.com/radsportfiles/file/18859162629.pdf
    • http://lideparts.com/userfiles/file/1627431117.pdf
    • https://www.escon.it/wp-content/plugins/super-forms/uploads/php/files/c1800ae9abae6c3118006f0f3cbd2240/74927617185.pdf
    • http://dgjinhak.kr/DATA/upload/files/202106070713414458.pdf
    • http://mecateengenharia.com.br/ckfinder/userfiles/files/miwewibojadenobobav.pdf
    • https://weeb.nu/userfiles/file/60116153685.pdf
    • http://sieuthikhoacaocap.vn/upload/files/44271311734.pdf
    • http://inewbus.com/wp-content/plugins/super-forms/uploads/php/files/kr5o8kiq3kqe0jj4mst6pj40r1/94683017628.pdf
    • https://verandapattaya.com/userfiles/files/99951936996.pdf
    • http://3bbb.fr/ckeditor/upload/files/25752390294.pdf
    • http://greaterdeliveranceministries1.com/clients/61527/File/porevilezozodopetotola.pdf
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607b2b03218be---xubatos.pdf
    • https://iva-vietnam.com/userfiles/file/11346710269.pdf
    • http://www.integra-cr.cz/administrace/ckfinder/userfiles/files/14809609688.pdf
    • http://flirtproducties.nl/ckfinder/userfiles/files/60078809483.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=resume+format+pdf+download+b.com
    • 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_off0000cff5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCFF5 16792 bytes
font_01_sfnt_off0000e80c.bin
0b51bc59764230590e03468a2a44501658b0823886b96663ea43607ca462f03f
pdf-font-stream PDF embedded font (sfnt) at offset 0xE80C 11128 bytes
font_02_sfnt_off000101e2.bin
cf8f902adab4772d53097a92c48c8090c92fa06ce27f1d0821e0bf845baced7d
pdf-font-stream PDF embedded font (sfnt) at offset 0x101E2 19288 bytes