Malicious PDF — malware analysis report

Static analysis result for SHA-256 5fcd25403ebc5744…

MALICIOUS

PDF

77.5 KB Created: 2021-09-22 17:48:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 31c664ccb87285ff7dcfb9ea264eeeb8 SHA-1: 9f88531cb7d61efef168f2fae7a9ae4f40a049c7 SHA-256: 5fcd25403ebc5744a0c241442a8c89f565bdefc487c315bc2a343ed7ba9e53d6
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests it functions as a link farm, likely to obscure the true destination or to appear as a legitimate resource. The embedded URLs, particularly the one hosted on amkboiler.com, are suspicious and likely serve as a lure to download a secondary payload. No scripts were extracted, but the overall structure points to a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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
  • 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
  • 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://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/ef93n45o8hf2i58rotdtkg8hn2/32633755494.pdf In PDF document text
    • http://vkp.ru/upload/global/file/57873838118.pdfIn PDF document text
    • http://3wsystems.com/shipinc/userfiles/files/52038114468.pdfIn PDF document text
    • http://haliburtonhighlandsheritage.ca/userfiles/file/42864579447.pdfIn PDF document text
    • http://111-orte.com/testarea/cwsCMSlight/media/files/wolerobobiworasemotige.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/vatuwinerimutugexexokazi.pdfIn PDF document text
    • http://impressivetravelvietnam.com/upload/files/zumuxupomepuwezel.pdfIn PDF document text
    • http://travelbilet.ru/sites/default/files/file/26110839908.pdfIn PDF document text
    • https://nhanloc.net/userfiles/file/jujijuxisi.pdfIn PDF document text
    • http://utuin.net/files/fckeditor/file/83321252540.pdfIn PDF document text
    • http://0048.pl/48files/file/nujipezesixi.pdfIn PDF document text
    • https://olterus.net/contents/files/gojoxukegesurimomogulad.pdfIn PDF document text
    • http://tea-ra.com/user_data/upload/save_image/files/jofonodolukevo.pdfIn PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/161418f750f46b---8193299925.pdfIn PDF document text
    • http://centonze-vini.com/userfiles/files/38805177781.pdfIn PDF document text
    • http://palletgoanloi.com/img-dn/files/92969309165.pdfIn PDF document text
    • http://rickgrisolia.com/userfiles/files/38464925962.pdfIn PDF document text
    • https://bbox.ru/images/shared/file/bivijujobefadolorinoras.pdfIn PDF document text
    • https://ladachess.ru/userfiles/file/janulixopozasaritigenadu.pdfIn PDF document text
    • http://dhleisure.com/ckupload/files/jigufivutonudasumosinu.pdfIn PDF document text
    • http://trubaopt.ru/content/file/81631204645.pdfIn PDF document text
    • https://www.blondel-bois.fr/ckfinder/userfiles/files/wetuxefefotopezudugobenu.pdfIn PDF document text
    • http://naasschoolofmotoring.ie/fckeditor/userfiles/file/danitesesanixotokiwuxuko.pdfIn PDF document text
    • https://fullprotec.com/ckfinder/userfiles/files/40871181953.pdfIn PDF document text
    • https://fajanav.com/aym_image/files/2213011745.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=android+development+interview+questions+you+ll+most+likely+be+askedPDF 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_off0000c9fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9FB 11280 bytes
SHA-256: 77f45004d5c939b85d4dcaf88c4636c21a4914e4239ff6dfe1046aca7fd336c3
font_01_sfnt_off0000e418.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE418 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fc2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC2A 16928 bytes
SHA-256: d46026e2bc563dd550e9fd86c501fdb4da7b0f07455306f44d6d84dc4993269a