Malicious PDF — malware analysis report

Static analysis result for SHA-256 28cd2757776091c8…

MALICIOUS

PDF

88.3 KB Created: 2021-07-21 03:43:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 9f1474c76da8c957e3a4c7466bf3e2b6 SHA-1: a0b19a8b8fa1f48c6204151dcac3002e6cdcf885 SHA-256: 28cd2757776091c8432207e1b74b382b749825444bc7b9f73772c4e543f2d95e
196 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress sites and other domains, indicating it functions as a link farm. The heuristic 'PDF_RANDOM_URL_LINK' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest these links are intended to lead users to malicious content or phishing pages. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://ippon.lv/uploads/File/85067413358.pdf In PDF document text
    • https://ddshower.com/ckfinder/userfiles/files/94963617028.pdfIn PDF document text
    • http://manufim.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1609d3d7376e95---43434809968.pdfIn PDF document text
    • http://csc0311.com/userfiles/file/20210613063233_ugmuag.pdfIn PDF document text
    • http://myarrahnu.com/mo_images/files/44711703622.pdfIn PDF document text
    • http://cinstech-inspect-survey.com/fckeditor_userfiles/file/raxigigujeso.pdfIn PDF document text
    • https://www.horisunmauritius.com/wp-content/plugins/super-forms/uploads/php/files/bfa4fa6748cb087a827774fb75525b7f/82287787738.pdfIn PDF document text
    • https://anzmrrn.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a9e41eb564e---61141778430.pdfIn PDF document text
    • https://sidexsideaudio.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d3c505ac0da---94457296243.pdfIn PDF document text
    • http://bjeclinic.com/ckfinder/userfiles/files/viwevep.pdfIn PDF document text
    • https://2acontractor.it/images/file/71244150734.pdfIn PDF document text
    • http://doublehappyvstheinfinitesadness.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608905bb28516---mirumuzefog.pdfIn PDF document text
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/173050e123468f9961507cf9e90dc8f8/70745734009.pdfIn PDF document text
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/16089d851511bd---felome.pdfIn PDF document text
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/160810e3614fcd---39923718652.pdfIn PDF document text
    • https://www.dolphinrfid.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2aed5a89c9---52910421850.pdfIn PDF document text
    • https://www.stamfordtaxis.com/wp-content/plugins/super-forms/uploads/php/files/2l09orlu4feopn4c11c5q5mofi/6104938348.pdfIn PDF document text
    • http://www.skup.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609a0e4405396---87284509162.pdfIn PDF document text
    • https://gauravkankariya.com/wp-content/plugins/super-forms/uploads/php/files/1554cgh0h3hf8nd0fbgu8qhhl7/zoburexapizibimupepev.pdfIn PDF document text
    • http://kstarsmall.net/userfiles/file///30250012105.pdfIn PDF document text
    • http://chokmanee.com/userfiles/file/40980942254.pdfIn PDF document text
    • https://orangcar.com/app/webroot/upload/files/bevopem.pdfIn PDF document text
    • http://dok-vo.ru/userfiles/file/48674777909.pdfIn PDF document text
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/160848c7ac106e---28070232583.pdfIn PDF document text
    • http://chnli.tw/CKEdit/upload/files/37421246082.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=organelle+found+only+in+plant+cellsPDF 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_off0000f55c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF55C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010d73.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D73 11032 bytes
SHA-256: 08e4128b1ce419dbab8c212bb0633d917da1a806ce813d4e779de786d8a112bf
font_02_sfnt_off00012716.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12716 17420 bytes
SHA-256: f1364f18ee153dd94ff82b08955ec02f2387ad124a44bd7725c682e1f723b264