Malicious PDF — malware analysis report

Static analysis result for SHA-256 c239d56cb20d721f…

MALICIOUS

PDF

84.7 KB Created: 2021-09-17 07:52:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 8d9473c0a21bceadf9f75d38fefbc3d3 SHA-1: 5cabe697604177e3c2c50de56b935eac85dc4c57 SHA-256: c239d56cb20d721f467bc2d43dce99be1f87cd4fad2efb5263a3a300dcaf4a3d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, and exhibits characteristics of a link farm on disposable hosting. It contains numerous embedded URLs pointing to external domains, suggesting an intent to redirect users to potentially malicious websites. The PDF structure and embedded content, though heavily obfuscated, are consistent with phishing or malware distribution lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://inwebjor.ru/uplcv?utm_term=stream+justice+league+dark+apokolips+war PDF link annotation
    • http://gr-chem.com/upload/files/78306902111.pdfIn PDF document text
    • http://afghansolar.com/userfiles/file/461283520.pdfIn PDF document text
    • http://www.mbk-montage.nl/ckfinder/userfiles/files/sepajagesixajab.pdfIn PDF document text
    • http://www.tivafa.hu/upload/file/89681577240.pdfIn PDF document text
    • http://gaestehaus-am-erlkoenig.de/img/editor/file/73018780482.pdfIn PDF document text
    • http://madmojo.com/fckupload/file/56934880610.pdfIn PDF document text
    • http://xn--b1agjlwjc3g.xn--p1ai/ckfinder/userfiles/files/netekomotaseziwakorekoj.pdfIn PDF document text
    • http://daivupaint.com/img-chamthi/files/93016619402.pdfIn PDF document text
    • http://protok.pro/upload/files/18782251367.pdfIn PDF document text
    • https://ikansambel.com/contents/files/26182644005.pdfIn PDF document text
    • http://straps.by/ckfinder/userfiles/files/26511963756.pdfIn PDF document text
    • http://talentfuturesservices.com/sharpinstitute/images/files/26716559863.pdfIn PDF document text
    • http://mgmkt.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161412abbbe886---59762937354.pdfIn PDF document text
    • http://iranjobex.com/cache/fck_files/file/19585671717.pdfIn PDF document text
    • http://enricobarraco.com/files/mekuluvesasabo.pdfIn PDF document text
    • http://veterky.ru/ckfinder/userfiles/files/kigenikutesuf.pdfIn PDF document text
    • https://pirkitpadangas.lt/ckfinder/userfiles/files/32633730868.pdfIn PDF document text
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/6a839toavrqfmcgkac5n3k1m14/kemekugoweganonegawe.pdfIn PDF document text
    • http://songhakbbq.com/uploads/files/sonazijonipiwixiwewiz.pdfIn PDF document text
    • http://belean.pl/userfiles/file/50731960296.pdfIn PDF document text
    • http://thestarbusan.com/FileData/ckfinder/files/20210911_68E581DFC13BC436.pdfIn PDF document text
    • http://mycoapaisyl.com/webimages/files/46517911245.pdfIn PDF document text
    • http://olguanaokulu.com/upload/file/dakutopamubuzuwetitarop.pdfIn PDF document text
    • http://palazzodiaz.com/userfiles/files/fivowoserizazazinirulolux.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_off0000e104.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE104 18868 bytes
SHA-256: 3bb609b2a7d4a8fd91eb279dc86180eef6f8ac8b06af1b54e329407f7f48c091
font_01_sfnt_off00011290.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11290 11236 bytes
SHA-256: 0ec2f2c55923ca00d65bd9ce3a602102c5969f3ac4f224d8f77eaa1e3cc9bda7
font_02_sfnt_off00012cc2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12CC2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1