Malicious PDF — malware analysis report

Static analysis result for SHA-256 f1040efb4f405146…

MALICIOUS

PDF

92.7 KB Created: 2021-10-09 17:26:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: b5212c961bf399f661a78e935c46a481 SHA-1: 38d47f3e7f09695eed872be0d10831b791e9c4fb SHA-256: f1040efb4f40514602386867dd37d3af4d35b02e4386dca1ea282c3e56bdec92
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample is a PDF file flagged by ClamAV as a phishing trojan and by an ML classifier. It contains a large number of embedded URLs, many of which point to domains that appear to be part of a link farm, a common tactic in phishing and spam campaigns. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically identifies this behavior. No scripts were extracted, but the presence of numerous external URIs suggests the document is intended to redirect users to malicious websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9806

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://krisoc.ru/uplcv?utm_term=new+words+with+their+meanings PDF link annotation
    • http://mitsubishilongbien.vn/images/ckeditor/files/74366567447.pdfIn PDF document text
    • https://casasholidays.com/scgtest/team-explore/uploads/files/fejefore.pdfIn PDF document text
    • http://waycreon.net/bhaskar/yii/upload/files/xetulopi.pdfIn PDF document text
    • http://wojno-stal.pl/pliki/file/3595407122.pdfIn PDF document text
    • http://aqbnb.com/uploadfile/file/34592777099.pdfIn PDF document text
    • http://highlevel.pl/userfiles/file/nofamuxetu.pdfIn PDF document text
    • http://kidzcastleschool.com/singhania/downloads/file/98577794901.pdfIn PDF document text
    • https://duproject.com/uploadEditor/files/luvalirotawedozegof.pdfIn PDF document text
    • https://holcom-solar.com/webroot/img/files/95205511687.pdfIn PDF document text
    • https://ismart99.net/upload/files/taxuxeralidadimusigalem.pdfIn PDF document text
    • http://bobmeetin.com/media/galleries/files/74759835284.pdfIn PDF document text
    • http://tai-yang.tw/taiyang/upload/file/ledinejevazoxanilupudan.pdfIn PDF document text
    • http://luyenthidhcanhsat.com/Images_upload/files/70734394815.pdfIn PDF document text
    • https://gsacademy.ge/uploads/files/20220881244.pdfIn PDF document text
    • https://keralahappyjourney.com/ckfinder/userfiles/files/roxosemiladukuduwu.pdfIn PDF document text
    • http://devison-matras.ru/upload/file/80130163700.pdfIn PDF document text
    • https://voxel-avocats.fr/uploads/file/In PDF document text
    • http://tbeaindia.com/userfiles/file/3217352096.pdfIn PDF document text
    • http://pferdefreunde-brueckenhof.de/sites/default/files/userfiles/file/26426206781.pdfIn PDF document text
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/161406cd466be6---34911771576.pdfIn PDF document text
    • http://finadev-groupe.com/userfiles/file/38709884126.pdfIn PDF document text
    • http://amunt.madteam.net/ckfinder/userfiles/files/53491944735.pdfIn PDF document text
    • http://svadbavmoskve.com/content/xuploadimages/file/mibuminuge.pdfIn PDF document text
    • https://eseninternational.com/uploads/files/zulit.pdfIn PDF document text
    • http://edituj.cz/res/file/41425219275.pdfIn PDF document text
    • http://pilanatofishing.com/home/sandbox/domains/shelter.sandbox.tritek.hk/public_html/ckfinder/userfiles/files/gekogozimosixunolitox.pdfIn PDF document text
    • https://paeonia.ch/userfiles/files/tusafisegomizo.pdfIn PDF document text
    • http://quesnelfoundation.ca/userfiles/file/kipuliwadaruv.pdfIn PDF document text
    • 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_off0001035a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1035A 19128 bytes
SHA-256: c8681a09bb9203e08944fbba3bbbce026720fd1a3c2d2fb2054a8bf9e92fd954
font_01_sfnt_off000134e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x134E1 10712 bytes
SHA-256: b98777d037479751ba5e8ef200d96a365870ab883a74643404d2a65211ef0e50
font_02_sfnt_off00014d26.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14D26 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1