Malicious PDF — malware analysis report

Static analysis result for SHA-256 1a3f1d6d882d83ac…

MALICIOUS

PDF

84.8 KB Created: 2021-08-13 00:26:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-17
MD5: 6468a8f492ebc5a3df2c4a4e748ec711 SHA-1: d5c2486209b32b3a7b8962fbdeaeec8435cc824e SHA-256: 1a3f1d6d882d83ac3d99ae7eb39db465d058d610fa1f835844479097f1384cfd
156 Risk Score

Malware Insights

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

The sample was detected by ClamAV as a phishing trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous links, many pointing to potentially compromised WordPress upload directories or disposable hosting, suggesting a link farm designed to redirect users. The PDF structure itself does not contain readable content, but the presence of external links and the high detection scores strongly suggest it's used to facilitate phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

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
  • 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.
  • 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 http://kimbuunguyen.com/uploads/userfiles/file/nimimiporajikogedoxag.pdf In PDF document text
    • http://ecbpolska.pl/wp-content/plugins/super-forms/uploads/php/files/801dbbba0f99f55a87c1b6bcb30bf181/nosurojumur.pdfIn PDF document text
    • https://thetitangroup.ca/wp-content/plugins/super-forms/uploads/php/files/4c9706fe3efc9eb2307318823e564ccb/fuzefinuluz.pdfIn PDF document text
    • http://ikhmongol.mn/ckfinder/userfiles/files/gosinizavuzedikiwugo.pdfIn PDF document text
    • https://nikken-engineer.jp/export/sd205/www/jp/r/e/gmoserver/8/6/sd0748886/nikken-engineer.jp/fckeditor/upload/file/83015600726.pdfIn PDF document text
    • https://stollerco.com/testingsites/advantage_aviation/assets/media/file/kajedetebaxafagisez.pdfIn PDF document text
    • https://www.litesourcenc.com/wp-content/plugins/super-forms/uploads/php/files/cf624d942a11a0ec28b5d2e3ed7ad10d/nowikewewukolivanoziju.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/3quml9pjpmhvoo8djbhht7jvj7/37655686668.pdfIn PDF document text
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160c6c75f3ea48---67181043314.pdfIn PDF document text
    • http://kronikarp.pl/ckfinder/userfiles/files/bivosusogixako.pdfIn PDF document text
    • https://appchecar.com/ckfinder/userfiles/files/nosejoxawatupipatutebewug.pdfIn PDF document text
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f1094d88e6---68122351838.pdfIn PDF document text
    • http://kaushalacademy.org/ckfinder/userfiles/files/wixit.pdfIn PDF document text
    • https://lion-trading.co.uk/wp-content/plugins/super-forms/uploads/php/files/r3ii538u8lprjrdtatnjkc3382/47751368880.pdfIn PDF document text
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607cf35b0ba3c---25168455150.pdfIn PDF document text
    • https://elitteaccesorios.com/wp-content/plugins/super-forms/uploads/php/files/j07itigcbr8na0j4s51l880asf/zagewuvolej.pdfIn PDF document text
    • https://www.themeshcowork.com/wp-content/plugins/super-forms/uploads/php/files/2d8daa083fa969914273b0632301480d/muwuke.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/160e85289e1ca9---gawevi.pdfIn PDF document text
    • https://www.medipratik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d2f9960e189---nibija.pdfIn PDF document text
    • https://conexkarvan.com/cache/fck_files/file/66456514138.pdfIn PDF document text
    • https://tlpnw.com/wp-content/plugins/super-forms/uploads/php/files/9c7be308b77c8475359bb6ba052f7d34/79197027274.pdfIn PDF document text
    • http://hanasushi6.com/uploads/files/nuzakuvi.pdfIn PDF document text
    • https://414movement.com/wp-content/plugins/super-forms/uploads/php/files/0896ee1dfc39c21de7ec4e53b54f53dc/filikapuxo.pdfIn PDF document text
    • https://hps-gruppe.com/wp-content/plugins/super-forms/uploads/php/files/og3lac5p4nn9o0r6iurb9vq3uc/14145135505.pdfIn PDF document text
    • https://alatheir.com/atheirwsfiles/file/ralamarasunufipanazawomos.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160ac4ccaf1ec0---90146661301.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=redfield+revolution+3-9x50+manualPDF link annotation
    • 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_off0000e684.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE684 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fe96.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE96 16800 bytes
SHA-256: 3dd8ed54d22267dddd99402b7547853cc9de445dc40ad17baa6dfa8c3d7279e1
font_02_sfnt_off00012a68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A68 11292 bytes
SHA-256: 682bb1a42cb044595de2fd3cfe01cad5c254e1f489e7b248f09a2448c3c630ab