Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f8456ba4aa0d083…

MALICIOUS

PDF

81.1 KB Created: 2021-08-17 16:07:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 61803a184b1943afc9c7398bbc83699f SHA-1: a7ed4e0c67e44e4d7bb1c86dd86db211c1ca9c9e SHA-256: 4f8456ba4aa0d08317e9d0598adb9beab166440b3c43dc4926b156556b64d52c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, with numerous embedded URLs pointing to compromised CMS uploads and disposable hosting. These links likely serve as a lure to direct users to phishing sites or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

Heuristics 6

  • 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.
  • 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://dkyangmei.com/uploadfile/file/2021062000083573499.pdf In PDF document text
    • http://maidnheaven.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608507ce45896---xasunisefoweg.pdfIn PDF document text
    • http://stoewebdesign.no/userfiles/file/sixewulilipajifade.pdfIn PDF document text
    • https://www.apartamentselsllacs.com/wp-content/plugins/super-forms/uploads/php/files/0i6ljve871lrl4ohp0gr05vmbp/76998655891.pdfIn PDF document text
    • http://www.moyekolodin.com/files/90114358082.pdfIn PDF document text
    • http://zawayakw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ef351b1c8e---82841234739.pdfIn PDF document text
    • https://www.pal-kont.hu/wp-content/plugins/super-forms/uploads/php/files/3c2d1485eb3e7017ae1403fd61c75d41/61140256661.pdfIn PDF document text
    • http://challendor.com/fckeditor/upload/file/sulibufofifu.pdfIn PDF document text
    • http://whitebearlakeclassof1970.com/clients/0/05/05755deafc47004aae723e515cf08a6f/File/4025657266.pdfIn PDF document text
    • https://camping-du-lac-dijon.com/fichiers/99963581198.pdfIn PDF document text
    • http://educasters.co/ckfinder/userfiles/files/18551373630.pdfIn PDF document text
    • https://sealordhotels.com/ckfinder/userfiles/files/95217420295.pdfIn PDF document text
    • http://tianfonmm.com/d/files/43457487859.pdfIn PDF document text
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/b8d606fcbf9b736e53edb47d54f4570c/2142073764.pdfIn PDF document text
    • http://aldobini.it/userfiles/files/rivuniletotunezer.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa5ea0d4182.pdfIn PDF document text
    • https://infoenergie-loire.org/userfiles/file/tojatulu.pdfIn PDF document text
    • https://stollerco.com/testingsites/advantage_aviation/assets/media/file/74069769921.pdfIn PDF document text
    • http://quanhoangtsi.com/upload/quangtri/files/23919838284.pdfIn PDF document text
    • http://eske.hu/wp-content/plugins/formcraft/file-upload/server/content/files/160bfc2046565e---7986757410.pdfIn PDF document text
    • http://michelschuurmans.nl/images/uploads/file/mojejibam.pdfIn PDF document text
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16094176aad276---5275179345.pdfIn PDF document text
    • https://karinbentum.nl/uploads/file/25092043214.pdfIn PDF document text
    • https://vietspices.asia/uploads/files/62284003614.pdfIn PDF document text
    • http://asbu.net/uploads/FCK_files/file/kinexagazepugumebanuta.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d30e05c0b7---73559307796.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=http+client+get+method+example+javaPDF 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_off0000d889.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD889 17120 bytes
SHA-256: 3a61cc24827321fbff44254d71b73ffeb5ef16b24d2c8c9ceaa7e9ff59cf3982
font_01_sfnt_off00010576.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10576 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011d8d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D8D 10980 bytes
SHA-256: 6c5a31825fde2615f06192f2ea97a199c92bc617496272f008cd55c95477fa55