Malicious PDF — malware analysis report

Static analysis result for SHA-256 9f90043bba6901ab…

MALICIOUS

PDF

81.4 KB Created: 2021-09-07 01:54:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: f44899f2c5454c8bc3327ba7ef68b99a SHA-1: 9092c154aba157f57e3efcf20d2bb72b7d1b9292 SHA-256: 9f90043bba6901ab10655505945ca6d06417386d2fd3a2aea53611829cd55acf
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. The document functions as a link farm, containing numerous embedded URLs that point to external sites, many of which are hosted on compromised CMS upload directories. The primary attack pattern observed is the use of these links to direct users to potentially malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://honghow.com/ckfinder/userfiles/files/85332653943.pdf In PDF document text
    • http://xn--b1agjlwjc3g.xn--p1ai/ckfinder/userfiles/files/tivifagegide.pdfIn PDF document text
    • http://xn--9i1b14lzokxjcrti5um.com/upload/fckeditor/file/73574411830.pdfIn PDF document text
    • http://savitapiti.org/ckfinder/userfiles/files/wubab.pdfIn PDF document text
    • https://kantankacreative.com/wp-content/plugins/super-forms/uploads/php/files/f1330dbf371eeb15b37c597ee27e6ff0/3019635296.pdfIn PDF document text
    • https://nationalshield-uae.com/userfiles/files/korelanabusasexevuxet.pdfIn PDF document text
    • http://penzionriverside.cz/files/file/64371108383.pdfIn PDF document text
    • https://riolospettacoli.it/filesUploads/file/kavufujizuxejikekogek.pdfIn PDF document text
    • https://aspirans.com/files/file/mukexopafotasulogozo.pdfIn PDF document text
    • http://www.playerclub.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a5a471f11a0---koxogaz.pdfIn PDF document text
    • http://www.suffaheducation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f4acd1ef5b---jajujorivedilejezogukove.pdfIn PDF document text
    • http://ekopaczka.pl/imgbrama/files/94524598418.pdfIn PDF document text
    • http://herodumpsterrental.com/wp-content/plugins/super-forms/uploads/php/files/4b52c8dd9d1d51fc6f72e22279511f90/duwoxoxojedofusado.pdfIn PDF document text
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a15c0d203c6---nisukiketumodazepolaveto.pdfIn PDF document text
    • https://sportnazona.bg/f/uploads/files/47421827211.pdfIn PDF document text
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1609687f7f3b7e---xuvojusotimuwezapika.pdfIn PDF document text
    • http://sntaviator.ru/ckfinder/userfiles/files/nazeputusedasudonode.pdfIn PDF document text
    • http://bm-shower.com/userfiles/files/76759744086.pdfIn PDF document text
    • http://amon-syotengai.com/userfiles/file/sikigikut.pdfIn PDF document text
    • https://www.18fire.com/wp-content/plugins/super-forms/uploads/php/files/ea89a7d5558f98e33f9ae125c899bd63/90337007641.pdfIn PDF document text
    • http://sinhadventure.com/uploads/file/14027197150.pdfIn PDF document text
    • http://obasekiestates.com/UserFiles/file/67329955221.pdfIn PDF document text
    • https://www.abaco-engineering.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609086b9b0b82---mejaburosituxuve.pdfIn PDF document text
    • http://kaowei.tw/image/files/20210529_104238.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=quality+improvement+project+charter+worksheetPDF 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_off0000d470.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD470 11288 bytes
SHA-256: 8e60a181070433cb1ebfc6dba90f017dffdf2c6d3a9ecd962d65ec1a45f0d0c4
font_01_sfnt_off0000eee5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEE5 18232 bytes
SHA-256: 1d7b7bfc723928cfcc5c0dbcecef68ecf071acf2afd3bf07cf55bf1fc16774a4
font_02_sfnt_off00011dfb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DFB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1