Malicious PDF — malware analysis report

Static analysis result for SHA-256 de21fb1cbfd36569…

MALICIOUS

PDF

86.6 KB Created: 2021-09-17 07:06:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 328c6caeba38b020e10d8d33d4e02517 SHA-1: ae04e541aa52cfafad9323fd2892d3e1c6d4db1e SHA-256: de21fb1cbfd365695117b618ad7df1cef9e693bcf2eef99cbbe0100b923b8c0e
156 Risk Score

Malware Insights

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

The sample was identified as malicious by a ClamAV detection and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, with numerous embedded URLs pointing to compromised CMS uploads and disposable hosting. These links likely serve as lures for phishing or to distribute further malware, aligning with spearphishing attachment and malicious link attack patterns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9922

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://torrentclub.vip/wp-content/plugins/super-forms/uploads/php/files/0nk7a3n8udpbk7624mhjvnqpb5/34689790129.pdf
    • http://ceramicaartisticamarsalese.it/userfiles/files/dugafadokab.pdf
    • http://kelakewangshangduchang.a9188.com/upload_files/art_files/files/20210911_135948.pdf
    • https://tuoitre.bacgiang.gov.vn/lib/ckfinder/files/rejanuzubuwupefipotom.pdf
    • https://floridagreatescape.com/media/file/bitofapixaroxu.pdf
    • https://il-gusto.com/images/file/55303709354.pdf
    • http://spadhotel.com/basefile/spadhotelcom/files/86687209864.pdf
    • http://metabolitplus.ru/files/file/votusujirojamiben.pdf
    • https://havadisname.com/upload/ckfinder/files/rugetuvaviwaxidalenekujo.pdf
    • http://zhouzhuank.com/v15/Upload/file/2021916429533317.pdf
    • https://www.supremecaravans.com.au/application/third_party/ckfinder/userfiles/files/sekalulebejuxijezusov.pdf
    • https://pikhospital.com/ck_uploads/uploads/files/14278123293.pdf
    • http://kerrya.com/ckfinder/userfiles/files/musewafobobamegozo.pdf
    • http://architettoannalisatinelli.it/userfiles/files/rarozib.pdf
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/196fe0d0a029e8c1868939489e20d0d0/ganabon.pdf
    • http://orderkai.com/uploads/files/musiforawafebexame.pdf
    • https://kapokcmassage.com/uploads/files/202109031418165232.pdf
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612eb2cd51623---85309284411.pdf
    • https://leuphuotcamap.com/uploads/image/files/papanum.pdf
    • https://infiniteprospects.com/FCKeditor/file/28242055698.pdf
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a112ee9f42---96115814521.pdf
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e4d43e20a5---fizaso.pdf
    • https://sharidendesignasphalt.com/wp-content/plugins/super-forms/uploads/php/files/d8e834c304e1d6c8d19066587b95c355/teguvurifewilo.pdf
    • http://unibox.lv/files/text/92996048958.pdf
    • http://everest-c.ru/ckfinder/userfiles/files/vigitotubejag.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=nakama+2+pdf
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ce2d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCE2D 16792 bytes
font_01_sfnt_off0000e643.bin
a263921a23be77182cdbf3e40bb325e7facc1df779a623911a98d47b0ccbeaea
pdf-font-stream PDF embedded font (sfnt) at offset 0xE643 9988 bytes
font_02_sfnt_off0000fc68.bin
3d49d8a85bedd617e1b4dd847264659a8c297f1071ed68a1add12d56e6ffae38
pdf-font-stream PDF embedded font (sfnt) at offset 0xFC68 22952 bytes
font_03_sfnt_off000136ea.bin
01cd0e4798e93fb086042d610f43ddeed7bf091af48aa863f5c4a4f61b651684
pdf-font-stream PDF embedded font (sfnt) at offset 0x136EA 16232 bytes