Malicious PDF — malware analysis report

Static analysis result for SHA-256 b43f23e61744b186…

MALICIOUS

PDF

77.2 KB Created: 2021-09-17 07:28:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: eca9ca5ab0a5ee33d910c6b76ce30234 SHA-1: 03966eaf5d218314bd0d058848fed2bab61c8a21 SHA-256: b43f23e61744b1862ddf3ac7d68c133d15f48b8f9a4baff3d2ea3fbe50f340a5
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating it's a phishing or trojan delivery mechanism. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress uploads and disposable hosting, likely to obscure the ultimate destination and evade detection. The primary goal appears to be directing users to external sites through deceptive means.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9901

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://immopolignano.lu/images/wilanudixenelokabiwizip.pdf
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161303ab2029f4---sorono.pdf
    • https://protraderin.com/userfiles/file/43904138436.pdf
    • http://dpnovelty.com/upload/files/loregonoj.pdf
    • http://rutka.pl/media/upload/files/c04504be8a6e4494edfe878948c3e51c.pdf
    • http://hocikto.info/userfiles/file/77827952446.pdf
    • http://quangcaovuanh.com/vietkiendo/upload/file/zajog.pdf
    • http://parkwestresidences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b86b060df3---daxis.pdf
    • https://endobible.com/userfiles/file/satekozow.pdf
    • https://alutat.com/data/file/begoxag.pdf
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/41cbaae078f7efbce933e0d69c7b4fe3/58374360902.pdf
    • http://automsystem.com/UploadFile/file/20210912081147633.pdf
    • http://szintai.hu/ckfinder/userfiles/files/pajilikadezawop.pdf
    • https://vegas-shop.net/uploads/files/karabegud.pdf
    • http://xn--82ca1bkibi6eufn5bh1b7i3e.com/UserFiles/File/rukozabuzoximujewiraligo.pdf
    • http://nfrostov.ru/upload/files/neromoxelirovuxenugex.pdf
    • http://lamardaegu.com/upfile/user/file/3080922891.pdf
    • http://adria-ex.com/images/blog/file/74430329315.pdf
    • http://xn----ctbguteehkho5h.xn--p1ai/ckfinder/userfiles/files/43800775779.pdf
    • http://peggylittlelawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/62978874752.pdf
    • https://cjsc.se/ckfinder/userfiles/files/digegefur.pdf
    • https://kakakmanis.com/contents/files/44097160483.pdf
    • http://degeninhotel.ru/admin/ckfinder/userfiles/files/57970379098.pdf
    • http://muszempilla.com/files/file/xafegabileraburururisu.pdf
    • http://hardiebase.com/uploads/assets/filefile/penodabexanibebevi.pdf
    • http://aibasavar.edu.bd/app/webroot/ckfinder/userfiles/files/13127066934.pdf
    • http://lynhuagiasi.com/Images_upload/files/rorivanunuli.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=unencrypt+pdf+without+password
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c567.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC567 16792 bytes
font_01_sfnt_off0000dd79.bin
e18175933d513060506c907082248f602de4423c118ec2f927e80d6e93f17b5c
pdf-font-stream PDF embedded font (sfnt) at offset 0xDD79 18628 bytes
font_02_sfnt_off00010d5b.bin
945182aed659c31c2db8213f79b9e8622d732e3dbfd9cef4d3e8d7ed0cbdf8a4
pdf-font-stream PDF embedded font (sfnt) at offset 0x10D5B 10976 bytes