Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3dfd50907531819…

MALICIOUS

PDF

81.8 KB Created: 2021-09-21 06:16:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 8dc4f71d244bd92575f20597a776ba54 SHA-1: 544f4d81922ca0a8c899b24a311f6d9941824d7f SHA-256: a3dfd509075318196aad46788de10fef99e61340f9aa59e28336720037e6928b
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as 'Pdf.Phishing.Trojan'. The file contains numerous embedded URLs, many of which point to compromised CMS upload directories on various domains, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and unreadable, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://www.moteco.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161362017be4ee---kowuwaxe.pdf In PDF document text
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/16144b215489c1---72558256357.pdfIn PDF document text
    • http://paliukenas.lt/i/File/jewujomonedalajip.pdfIn PDF document text
    • http://lscapital.it/images/file/50405526904.pdfIn PDF document text
    • http://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/3e59827983ab4283ac6da61af50d65d0/pikuzuf.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/c30u5lfhappfpvjb887cc85092/6506752527.pdfIn PDF document text
    • http://exito-opakowania.pl/userfiles/file/92959234237.pdfIn PDF document text
    • https://hyosungulf.com/uploads/file/3595505181.pdfIn PDF document text
    • http://huichem.com/ckfinder/userfiles/files/fusokosaruwovukexit.pdfIn PDF document text
    • https://atpl.aero/ckfinder/userfiles/files/dexupowefafejifovara.pdfIn PDF document text
    • https://moderator.lt/components/com_mijoshop/opencart/image/data/files/66055292275.pdfIn PDF document text
    • http://upsshop.ru/ckfinder/userfiles/files/zigiwuwuvujofon.pdfIn PDF document text
    • http://4998horo.gmmwireless.com/contents/files/12627256350.pdfIn PDF document text
    • https://nayyaralidada.net/alpha/ckfinder/userfiles/files/xogusimegeranototixuvepu.pdfIn PDF document text
    • http://lorichphoto.com/pictures/file/pumolazajarifu.pdfIn PDF document text
    • http://tythb.cn/uploadfile/files/nugile.pdfIn PDF document text
    • http://aedelsur.com/contenido/files/pojowowudufisetuxilupusan.pdfIn PDF document text
    • https://securitydm.rs/slicice/file/23715548684.pdfIn PDF document text
    • http://urgentcarepb.com/userfiles/file/53524223993.pdfIn PDF document text
    • http://www.oomedia.com.tw/ckfinder/userfiles/files/kekuvopepumakikulazoneras.pdfIn PDF document text
    • https://www.azulejositurry.com/wp-content/plugins/super-forms/uploads/php/files/kfvk273pghfputge6vvgkctup1/golozu.pdfIn PDF document text
    • http://balogmihaly.hu/UserFiles/file/36124377411.pdfIn PDF document text
    • http://de-ko-gmbh.com/ckfinder/userfiles/files/gamunuxawupej.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=john+wick+3+yify+subtitlesPDF 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_off0000cf61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF61 10864 bytes
SHA-256: fd0ea69565fec63d451cacb0ddface75c5e1429f1da25a6888f20b435c5bc6f0
font_01_sfnt_off0000e8a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8A0 21692 bytes
SHA-256: 6eea17c251e55f16b21f38c745f75e6391fe89cfe79e81a84b25e039ac0f45db
font_02_sfnt_off00012176.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12176 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1