Malicious PDF — malware analysis report

Static analysis result for SHA-256 53c7e7538682433f…

MALICIOUS

PDF

82.6 KB Created: 2021-09-20 12:13:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 4ba8407eb3730b841717c82426698835 SHA-1: df3b28456896ecef2db7cadd8134e64cb283db9d SHA-256: 53c7e7538682433ff10595b8b5fc1304d82c629d4ec99a306b85cb6117bc576a
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains numerous embedded URLs, many of which point to disposable domains and are structured as link farms, a common tactic for phishing or distributing further malware. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically indicates this behavior. While no scripts were explicitly extracted, the nature of the embedded URLs suggests an intent to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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://allytemp.ru/uplcv?utm_term=vidmate+apk+app+free+download PDF link annotation
    • http://chekeeh.ir/basefile/chekeehir/files/72210131236.pdfIn PDF document text
    • http://realfootball.gr/userfiles/file/34931833503.pdfIn PDF document text
    • http://sun-green.be/ckfinder/userfiles/files/35904075178.pdfIn PDF document text
    • https://saatyapi.com/upload/ckfinder/files/24076339829.pdfIn PDF document text
    • https://sarenpinler.com/calisma2/files/uploads/watotu.pdfIn PDF document text
    • https://ddshower.com/ckfinder/userfiles/files/jofarega.pdfIn PDF document text
    • http://phutungquanghieu.com/app/webroot/files/ckfinder/files/sojaluxuvixazufumuzadak.pdfIn PDF document text
    • https://gkia.org/kingkong/userfiles/files/wuzewujokabade.pdfIn PDF document text
    • http://teplo76.ru/uploads/file/322838524.pdfIn PDF document text
    • http://napiarsaigh.com/images/29027070608.pdfIn PDF document text
    • https://siangyun.com/upfiles/editor/files/92883068634.pdfIn PDF document text
    • https://denizlihorozu.com/resimler/files/57289426054.pdfIn PDF document text
    • http://studioiulianella.it/userfiles/files/81463772342.pdfIn PDF document text
    • http://sendedianqi.com/upload_fck/file/2021-9-18/20210918171227721263.pdfIn PDF document text
    • http://francescofesta.it/userfiles/files/nupipusipebuvomavulur.pdfIn PDF document text
    • https://derechosenred.org/aym_image/files/73894935294.pdfIn PDF document text
    • https://ecoinkworld.com/wp-content/plugins/super-forms/uploads/php/files/e868cf5c52ab45ffd7d3f6465c076406/23764973060.pdfIn PDF document text
    • http://sdhmladavozice.cz/userfiles/file/89259956274.pdfIn PDF document text
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/1614307d1103aa---95414876159.pdfIn PDF document text
    • http://auto-spec.ca/fck/file/80206131229.pdfIn PDF document text
    • https://tttinox.com/upload/userfiles/files/89649736650.pdfIn PDF document text
    • http://profstil.az/userfiles/file/kalikunegakubez.pdfIn PDF document text
    • https://portoggitter.no/content/files/userfiles/file///69562173897.pdfIn PDF document text
    • http://bayzones.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/palutabijabinewugano.pdfIn PDF document text
    • https://drmiamiconnect.com/wp-content/plugins/super-forms/uploads/php/files/38ee058950e9969cb9f62413869558b8/56553793463.pdfIn PDF document text
    • http://agro-pasz.pl/ckfinder/userfiles/files/sivuwesoxelutexodasabake.pdfIn PDF document text
    • https://barrier.exma.cl/ckfinder/userfiles/files/75047464399.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_off0000dd40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD40 10636 bytes
SHA-256: c1e65a1bb21fa907164bcc4f326001b9856f0e67f50672fc69e1dc46fcdf293d
font_01_sfnt_off0000f596.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF596 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010da8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DA8 18248 bytes
SHA-256: 58192fa8c964ffce5ab8a465f987c01db8d7c23e5da81b47e3530a91615f1b2a