Malicious PDF — malware analysis report

Static analysis result for SHA-256 9f5c2e9cd41dc48c…

MALICIOUS

PDF

69.5 KB Created: 2021-09-30 16:53:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 00515e5fce1c5858adbde02bccc47414 SHA-1: a58b1cf7fdfae32d070fe3e16aa26bb583d639b0 SHA-256: 9f5c2e9cd41dc48c52e4005e2d507ddc10db5dce9e0e36429a1fbd9662070cec
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and ML classifiers indicated a high probability of maliciousness. Heuristics identified it as a link farm, with several URLs pointing to potentially compromised WordPress upload storage and other disposable hosting. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the presence of numerous external links strongly suggests an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://art4you.sk/editor_uploads/system/files/24734659278.pdf In PDF document text
    • http://www.xn----9sbkvfu2aex3d.xn--p1ai/ckfinder/userfiles/files/gexararipifibufaromajag.pdfIn PDF document text
    • http://packagingandfoodmachinary.com/userfiles/file/lafikotolaw.pdfIn PDF document text
    • http://fszhenjia.com/upfolder/e/files/20210916055718.pdfIn PDF document text
    • http://cuuhoatudong.com/upload/files/pulewekekumakav.pdfIn PDF document text
    • http://aprt1day.ru/file/66773381196.pdfIn PDF document text
    • https://jechrina.gr/FCKeditor/userimages/file/gikaratexokadujufexazujex.pdfIn PDF document text
    • http://haozuowenwang.com/imagefiles/file/tebisimifusunanita.pdfIn PDF document text
    • http://danies.ru/ckfinder/userfiles/files/durulazuxedudamirok.pdfIn PDF document text
    • http://sentai.cc/data/file/20210906_210307_483.pdfIn PDF document text
    • https://ladychief.com/wp-content/plugins/super-forms/uploads/php/files/ac7b75b17541441795142fcb2a7089e2/tepofipuleluvozeda.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/1612fd2d229898---zopovelona.pdfIn PDF document text
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1612eb9bbbccde---91068922674.pdfIn PDF document text
    • http://vce34.ru/attachments/file/fesefulotenifofolupog.pdfIn PDF document text
    • http://bakoca.hu/files/file/fobuvajijuwevalutuni.pdfIn PDF document text
    • https://cometgroupinternational.com/ckeditor/ckfinder/userfiles/files/36305046255.pdfIn PDF document text
    • http://npi-management.com/ressource/site-image/files/nubuwajexame.pdfIn PDF document text
    • https://ww150006.linebot.net/upfile/files/20210914145316.pdfIn PDF document text
    • https://livre-d-art.com/ckfinder/userfiles/files/jojinarirukugunolaf.pdfIn PDF document text
    • https://cmoretv.com/userfiles/favavilojuxu.pdfIn PDF document text
    • http://pekingtogo.com/uploads/files/donumenir.pdfIn PDF document text
    • http://syuncyoku.jp/upload/file/xobozimuxamixarafuguwus.pdfIn PDF document text
    • http://aunay-sous-auneau.fr/ckfinder/userfiles/files/29626574463.pdfIn PDF document text
    • http://ore-processing.ru/d/files/mabatojepuzif.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=brooklyn+nine+nine+freePDF 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_off0000b00f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB00F 16560 bytes
SHA-256: 45bf5f5ce12b3e5dc04d52a22da9a8e8f9e1c73595792b13238c7823c9faf020
font_01_sfnt_off0000da13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA13 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f22a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF22A 10040 bytes
SHA-256: 183c52b7d9e48efd66f67f799274adbbabee6edae6a0245fe00b38505392bac5