Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf93b4551d363958…

MALICIOUS

PDF

69.2 KB Created: 2021-09-11 21:21:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 898d52bbcb03be4d3dbba4551f28912e SHA-1: be063b8c643fdc9964125f64b4a1e03e7012f011 SHA-256: cf93b4551d36395860feda9bc12a038a3ea36ee2eae7939bab298379f199310f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by ML classifiers and ClamAV as malicious, with heuristics indicating it functions as a link farm directing users to numerous external PDF files. The presence of multiple unknown URLs suggests a phishing or malware distribution campaign. Although no scripts were explicitly extracted, the PDF structure and numerous embedded URLs point towards an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

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 http://integrotech.eu/zdjecia/file/14061794155.pdf In PDF document text
    • https://dabanbep.tanglehadong.com/upload/files/79864481178.pdfIn PDF document text
    • https://turkuazhost.com/calisma2/files/uploads/liviwinim.pdfIn PDF document text
    • http://reklama-v-sochi.com/ckfinder/userfiles/files/zexotorirokopuxamemosupub.pdfIn PDF document text
    • https://thanaclusterwestgate.leaddeehub.com/userfiles/files/73523288812.pdfIn PDF document text
    • https://ww150007.linebot.net/upfile/files/20210910143159.pdfIn PDF document text
    • https://www.southdownscellars.co.uk/ckfinder/userfiles/files/11743415710.pdfIn PDF document text
    • http://kbidc.kr/upload/editor/file/1630859584.pdfIn PDF document text
    • https://yenicekentkaplicasi.com/userfiles/file/pejebuf.pdfIn PDF document text
    • http://www.de.ruben.pl/ckfinder/userfiles/files/revekujupuxitopa.pdfIn PDF document text
    • https://markmont.eu/editor_uploads/system/files/71484989792.pdfIn PDF document text
    • http://goksirkrupskimlyn.pl/img/upload/files/namixurezarizuki.pdfIn PDF document text
    • https://www.leadercaravans.com.au/application/third_party/ckfinder/userfiles/files/rogetewaxedikakeruzegoja.pdfIn PDF document text
    • http://sumosushingrill.com/uploads/files/kitadiwos.pdfIn PDF document text
    • http://telesson.net/_UploadFile/Images/file/14962737943.pdfIn PDF document text
    • http://rejs2013.cycling-recycling.eu/imgturysta/files/66715276345.pdfIn PDF document text
    • https://mudateconmigo.cl/wp-content/plugins/super-forms/uploads/php/files/1f9f93bb2eda19ca0ae414bb27f3eb8a/23847352625.pdfIn PDF document text
    • https://matras-matrasych96.ru/admin/ckfinder/userfiles/files/71731326252.pdfIn PDF document text
    • http://abwingsbuffalo.com/uploads/files/32645805363.pdfIn PDF document text
    • http://uniquehotelsolutions.com/files/others/dekebase.pdfIn PDF document text
    • https://cuisinescartier.ca/upload/editor/file/28174401488.pdfIn PDF document text
    • http://trubaopt.ru/content/file/wuwujetikanumatug.pdfIn PDF document text
    • https://store-connector.com/_upload_bilder/_filemanager/file/lexepojuvopenupafavegimid.pdfIn PDF document text
    • http://www.accl-calibration.com/login/ckfinder/userfiles/files/femigobogitajoti.pdfIn PDF document text
    • https://pcetravel.com/files/file/bazelub.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131cdf2ac490---61837081699.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=android+deleted+contact+recoveryPDF 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_off0000b312.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB312 14636 bytes
SHA-256: 2db922e9d04cf638016d09dd9c7333625dc4916e5e303086a8641683cbf5840b
font_01_sfnt_off0000d7ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7BA 10356 bytes
SHA-256: f021b785e6fca5caebc2067b44522d910dd2b55a1e4a260b0c798bfb0236c97a
font_02_sfnt_off0000ef3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF3E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1