Malicious PDF — malware analysis report

Static analysis result for SHA-256 4efdd9cb9afea0f8…

MALICIOUS

PDF

76.6 KB Created: 2021-10-07 22:48:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 7850ae6fd534c8f817492c355bc7ba09 SHA-1: e500563e0196f3dc3175007877e0a621f8f61143 SHA-256: 4efdd9cb9afea0f87e6dc62b45e1559394e79892bbb92692a757ae343cf43e04
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as malicious, including a high ML score and ClamAV detection. It contains a link farm pointing to various domains, many of which appear to be compromised or disposable hosting. The primary purpose seems to be redirecting users to external sites, likely for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://westernstudioservice.com/admin/userfiles/file/50755844110.pdf In PDF document text
    • http://color-gateway.com/userfiles/file/jikupikipezakawuxe.pdfIn PDF document text
    • https://www.nobleorthodontic.com/wp-content/plugins/super-forms/uploads/php/files/c533471e8504232d3868bd6bb5a9d986/14328804020.pdfIn PDF document text
    • http://hai-bi.com/uploads/files/202110062019402836.pdfIn PDF document text
    • https://dienhoanghean.com/upload/ck/files/73877310415.pdfIn PDF document text
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615d48f61ad82---39904102794.pdfIn PDF document text
    • http://benthanhsgfarm.com/images/uploads/files/7397325237.pdfIn PDF document text
    • http://ambvetsanprospero.eu/userfiles/files/85993630248.pdfIn PDF document text
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/e11ba10fb29bc14d1c927718753f1fe6/sazalebapulipikotariv.pdfIn PDF document text
    • https://angkortaxiservice.com/userfiles/file/17762782912.pdfIn PDF document text
    • http://foto-preiss.at/upload_files/files/9597491115.pdfIn PDF document text
    • http://www.ruben.pl/ckfinder/userfiles/files/31887523710.pdfIn PDF document text
    • http://union.travel/ckfinder/userfiles/files/rusukiwazo.pdfIn PDF document text
    • http://horizonpestservices.com/userfile/29669198891.pdfIn PDF document text
    • http://vkts.se/userfiles/file/gavabojimorafa.pdfIn PDF document text
    • https://zbmbudomont.pl/userfiles/file/wikodokejujepidixodaw.pdfIn PDF document text
    • https://ohcsi.com/ckfinder/userfiles/files/xiriwewufukiwij.pdfIn PDF document text
    • http://huijingweb.com/upload_fck/file/2021-9-10/20210910104514308019.pdfIn PDF document text
    • http://osmed.cz/app/webroot/files/files/nurinufaxaxurobutupibunip.pdfIn PDF document text
    • http://hamlineparkplaza.com/assets/amund/ckfinder/userfiles/files/wivenajakex.pdfIn PDF document text
    • http://shinhwajudan.com/userData/board/file/ripiwoxasawewejiteze.pdfIn PDF document text
    • http://sh8ke.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135be0085973---rajozunexuvotanivepab.pdfIn PDF document text
    • http://dztechfin.com/upload/file///tonakeniki.pdfIn PDF document text
    • https://bandai-k.com/userfiles/file/zagafomumejorejuvotox.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=batch+convert+pages+to+pdfPDF 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_off0000c3d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC3D4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dbe6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBE6 18584 bytes
SHA-256: 118a0b264debd4de5417379d8b592117c599de60732d2bf67681b4ff65d17e41
font_02_sfnt_off00010bd3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BD3 10880 bytes
SHA-256: b95a018bb334a34f0cd0850e730a7729245c800433fa792a7b758d9613c922ef