Malicious PDF — malware analysis report

Static analysis result for SHA-256 c85a4bf487fc8cb5…

MALICIOUS

PDF

70.5 KB Created: 2021-09-24 23:12:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: f9c9f5a9f4a0df1e391f45e25dcdd728 SHA-1: 3e6ede23f054aa667b4e4a42b36b1e6abfe1432a SHA-256: c85a4bf487fc8cb591c575c55e8f32db70d93ac377d8ec4fa4c9951d33c0e4ab
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised CMS upload storage and disposable hosting, suggesting a phishing or malware distribution scheme. The embedded URLs, while numerous, do not directly reveal the final payload, but their association with compromised sites is a strong indicator of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • 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.
  • 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://www.boldino-hotel.com/ckfinder/userfiles/files/mererit.pdf In PDF document text
    • http://ndfeef.com/radiant/mechimobiles/userfiles/files/pajedezok.pdfIn PDF document text
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614040db4a518---96183205457.pdfIn PDF document text
    • https://resttour.com/images/userfiles/files/zaduge.pdfIn PDF document text
    • https://kingdom.vn/userfiles/file/demawezelowelek.pdfIn PDF document text
    • http://zatacorp.com/upload/files/repipozorinunek.pdfIn PDF document text
    • http://andreevmag.com/wp-content/plugins/super-forms/uploads/php/files/073f197ea495080d1e991390871886bb/80456333639.pdfIn PDF document text
    • http://studiofranzoni.eu/userfiles/files/xuzubiwokexorexisive.pdfIn PDF document text
    • http://grafitym.kz/files/file/60350704982.pdfIn PDF document text
    • http://eternalcycle.com/FCKFiles/file/11277210482.pdfIn PDF document text
    • http://fcv-bo.org/data/fcv-bo/userfiles/file/23246067915.pdfIn PDF document text
    • https://leavereview.com/customerinterview/ckfinder/userfiles/files/gawinetodufedeze.pdfIn PDF document text
    • http://hatdesechia.com/storage/ckfinder/files/jigitomogafire.pdfIn PDF document text
    • http://nedvizhimost-v-sharm-el-sheikhe.ru/uploads/files/zixijil.pdfIn PDF document text
    • http://speckrepeg.by/UserFiles/files/mufelituzutow.pdfIn PDF document text
    • https://calmoinc.com/upload/editor/file/68331415225.pdfIn PDF document text
    • http://solo-reisen.com/media/images/file/60833963449.pdfIn PDF document text
    • http://xn--krmer-dnnebacke-1kb72b.de/files/file/41914792743.pdfIn PDF document text
    • https://viveironativodevicosa.com.br/ckfinder/userfiles/files/41114188598.pdfIn PDF document text
    • https://nghiepvu.udicmanpower.vn/uploads/news_file/pawogul.pdfIn PDF document text
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/aa5fa9af5084f3a3451cddb51a521c69/63339292044.pdfIn PDF document text
    • http://infas.cz/images/wiswig/file/78432273919.pdfIn PDF document text
    • http://gyuco.com/uploadfile/files/20210914_092506.pdfIn PDF document text
    • https://gangwontaxi.com/FileData/ckfinder/files/20210912_0F8825FEEBC92C84.pdfIn PDF document text
    • http://chinalabware.es/d/files/61295461012.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=how+to+view+private+instagramPDF 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_off0000b1d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1D6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c9e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9E8 16472 bytes
SHA-256: f4dcaf12548eca2c0372f4f7fc7a0084462894aec9519bc8d8b42ad30a528532
font_02_sfnt_off0000f3f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3F0 10692 bytes
SHA-256: ca2aa5db2462a0d77241e86de30f2c7c53336c6865ac7f31884f790fc2c2da40