Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac16403e82608e21…

MALICIOUS

PDF

80.9 KB Created: 2021-09-19 09:24:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: a39a9ef675dddc06f436da564167d2c5 SHA-1: 40ac9173d582dfa37df4747feebf3741952e1561 SHA-256: ac16403e82608e2199ec53353d43964d881d1190084feb4362268ff04d9af677
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File

The PDF file was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It functions as a link farm, containing numerous URLs that point to various websites, some of which are hosted on compromised WordPress upload storage. The presence of these links suggests an attempt to lure users to malicious or compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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 https://sankaibearing.com/userfiles/files/lenupomixigok.pdf In PDF document text
    • http://gsnursing.in/ckeditor/ckfinder/userfiles/files/13408085035.pdfIn PDF document text
    • http://stroi-sistema.ru/img/vitigisoge.pdfIn PDF document text
    • https://www.whoamiandwhyamihere.com/ckfinder/userfiles/files/josenazegej.pdfIn PDF document text
    • https://rux-thai.com/ckfinder/userfiles/files/6742891068.pdfIn PDF document text
    • https://triyoga-tv.ru/userfiles/file/gezuvaduwiwinuberisorujoj.pdfIn PDF document text
    • http://dalnoboy.net/data/filestorage/upload/files/91433992064.pdfIn PDF document text
    • https://californiaoptionsrealestate.com/wp-content/plugins/super-forms/uploads/php/files/6b5791aca02f8fa95e6fb795e803235f/14209976965.pdfIn PDF document text
    • http://kkc1.org/htdocs/cljr/data/files/balerana.pdfIn PDF document text
    • http://cngwalk.com/fckeditor/userfiles/image/66832448504.pdfIn PDF document text
    • http://albertf.madteam.net/ckfinder/userfiles/files/52529426704.pdfIn PDF document text
    • http://nbmounts.com/userfiles/file/1630960433.pdfIn PDF document text
    • https://tavcam.com/upload/ckfinder/files/67217315264.pdfIn PDF document text
    • http://tfforming.ru/d/files/wadilusevegawuzomof.pdfIn PDF document text
    • https://store-connector.com/_upload_bilder/_filemanager/file/bosojed.pdfIn PDF document text
    • http://uralcomservis.ru/crn_fls/crn_files/gogumofanobofamip.pdfIn PDF document text
    • http://yourhealthyanswer.com/ckfinder/userfiles/files/54881240587.pdfIn PDF document text
    • http://alacarte-design.de/userfiles/file/bivazudotafeta.pdfIn PDF document text
    • https://www.andeanskyline.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146cb58839c5---95250549201.pdfIn PDF document text
    • http://geluidsadviesnederland.nl/ckfinder/userfiles/files/17287458846.pdfIn PDF document text
    • https://maryamghiasi.com/images/upload/files/golakupodasexogokajuzup.pdfIn PDF document text
    • http://www.festivalmarrakech.info/wp-content/plugins/formcraft/file-upload/server/content/files/161415efa28b34---61115124385.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=verbs+that+start+with+the+letter+zPDF 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_off0000d93c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD93C 17788 bytes
SHA-256: f77b2324702740b3a79d8afb7e43fc2539e153c0debc77582d50da7cc830dc24
font_01_sfnt_off00010707.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10707 10236 bytes
SHA-256: d092bb798a7bfea122b84ed4100e9da4684f2b650f9808cc002fce661915f779
font_02_sfnt_off00011e3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E3E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1