Malicious PDF — malware analysis report

Static analysis result for SHA-256 28119e3fbf771238…

MALICIOUS

PDF

91.2 KB Created: 2021-09-16 14:47:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 5601b0a27ec8a27bc856ceb3cd5fcf67 SHA-1: 26d8322781923c1684ba886f8b0855971b97247b SHA-256: 28119e3fbf7712389ce11192cb8e16a76ef9da95921beb51e8f7bb7525d4ddfd
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and multiple external URIs, many of which are hosted on compromised or disposable domains, forming a link farm. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or directing users to malicious content. The presence of embedded JavaScript suggests it may be used to further obfuscate the malicious links or initiate further malicious actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://filipdegreef.be/uploads/files/liboxolumemejiboku.pdf In PDF document text
    • http://cistenivytahu.cz/upload/file/telefepafaxajetozu.pdfIn PDF document text
    • http://studioghittigargnano.com/userfiles/files/59100720237.pdfIn PDF document text
    • http://htwy.com/upload/file/34628441961.pdfIn PDF document text
    • http://paintmaster.hu/js/ckfinder/userfiles/files/3300394787.pdfIn PDF document text
    • http://rovitek.com/userfiles/file/40094475102.pdfIn PDF document text
    • http://studiobaldizzone.com/userfiles/files/surovozenisipugulu.pdfIn PDF document text
    • https://hiperaktivite.info/userfiles/files/kinexirapaguxevodibubape.pdfIn PDF document text
    • https://mytshirtcreator.com/app/webroot/files/file/34142071132.pdfIn PDF document text
    • https://kaptenhoki.org/contents/files/lakitevilafex.pdfIn PDF document text
    • http://seattledesis.com/fckeditor/file/dakuga.pdfIn PDF document text
    • http://ohdiabo.net/images/ckeditor/files/47481473955.pdfIn PDF document text
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/2gaomfv1ijkct0k41ckanh9s93/wamebusokofomavi.pdfIn PDF document text
    • http://thaiboxes.com/piceditor/file/relanodumito.pdfIn PDF document text
    • http://lahma.pl/_u/userfiles/file/pimexekodi.pdfIn PDF document text
    • http://megamento.com/_UploadFile/Images/file/ruzivit.pdfIn PDF document text
    • http://miraesusan.com/ckupload/files/52015485619.pdfIn PDF document text
    • http://yizhu580.com/ckfinder/userfiles/files/jataxejozewer.pdfIn PDF document text
    • https://www.tonygssoulfood.com/wp-content/plugins/super-forms/uploads/php/files/61aca686f4f6dfa99652e61e07a32b56/nifivoserer.pdfIn PDF document text
    • http://carneiro-sa.pnh.pt/js/ckfinder/userfiles/files/zuwuwuvibot.pdfIn PDF document text
    • https://kolkatanagariksammelan.org/ckfinder/userfiles/files/37626828603.pdfIn PDF document text
    • https://www.creativetalentnetwork.com/ckfinder/userfiles/files/bofuxomaja.pdfIn PDF document text
    • https://iringmalaysia.com/ckfinder/userfiles/files/95331908375.pdfIn PDF document text
    • http://lotuscourtpune.com/wp-content/plugins/super-forms/uploads/php/files/78349a3f8da27a1f1d05a1dd15016524/85134614708.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=internet+explorer+f%C3%BCr+androidPDF 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_off0000f985.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF985 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011197.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11197 20392 bytes
SHA-256: 07b19a7d993c5b853b30199cbb595a6175c46ee72b2e84f94c3f9d80df0f9b01
font_02_sfnt_off000144d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x144D8 10568 bytes
SHA-256: 079d596156c43dc141434223293f582d73aee4019c170b6face7350a4f776781