Malicious PDF — malware analysis report

Static analysis result for SHA-256 6f17636771fab628…

MALICIOUS

PDF

80.4 KB Created: 2021-09-15 18:28:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: f0f3b71d0f8e32556be79ffe24d70857 SHA-1: 2bcc5e4c72d81aac87718afd49cc35b033673fb7 SHA-256: 6f17636771fab6285dadc74f2f107ddfaf27b85a9aa33c8ced859905c1ae38ec
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The PDF contains numerous external URIs, with one specifically pointing to 'irlanc.ru' and containing 'install system certificate android' in the UTM term, suggesting a lure for users to download potentially malicious software. The presence of many distinct hosts and links within the PDF further supports a link farm or phishing attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://irlanc.ru/uplcv?utm_term=install+system+certificate+android PDF link annotation
    • http://nincity.de/inline/file/69698063625.pdfIn PDF document text
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612f84b28742e---54511535159.pdfIn PDF document text
    • http://www.barbazan-debat.fr/ckfinder/userfiles/files/66456344560.pdfIn PDF document text
    • https://parklanehotel.asia/userfiles/file/sewalijexodutopu.pdfIn PDF document text
    • http://orlickachata.cz/files/files/mafapevenamurotowip.pdfIn PDF document text
    • http://messtores.ca/fck_user_files/file/jivofavediweborexusiroxun.pdfIn PDF document text
    • https://transport.frontiermyanmar.com/sites/all/libraries/ckfinder/userfiles/files/zabofowu.pdfIn PDF document text
    • http://ideviceplus.nl/app/webroot/files/userfiles/files/zonafovozez.pdfIn PDF document text
    • http://agecarekorea.com/ckupload/files/fobelokona.pdfIn PDF document text
    • http://dailymaydemtien.com/userfiles/files/dunabaneg.pdfIn PDF document text
    • http://ty-universe.com/image/files/20210903_162154.pdfIn PDF document text
    • https://dogathermalhotel.com/resimler/files/9924850178.pdfIn PDF document text
    • http://kpghomerepairs.com/uploads/image/files/46483996206.pdfIn PDF document text
    • http://zelene-centrum.cz/webpagebuilder/ckfinder/userfiles/files/86971906885.pdfIn PDF document text
    • http://eviljoy.com/UserFiles/File/13562480395.pdfIn PDF document text
    • https://lideregitimpaketleri.com/calisma2/files/uploads/timefomofitanazukigozeg.pdfIn PDF document text
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613a077234824---98097759904.pdfIn PDF document text
    • http://wooshin.kr/uploaded/file/632640806613af6b5c1078.pdfIn PDF document text
    • http://busankid.com/webfiles/board/file///77738582980.pdfIn PDF document text
    • http://laihoawedding.com/app/webroot/upload/files/13361300169.pdfIn PDF document text
    • http://www.masozilina.sk/ckfinder/userfiles/files/23580437507.pdfIn PDF document text
    • http://ventima.ru/userfiles/file/73893645665.pdfIn PDF document text
    • https://promptcorporate.com/ckeditor/ckfinder/userfiles/files/672522020.pdfIn PDF document text
    • http://ormansagszive.hu/upload/file/faloxabirilad.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_off0000d42c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD42C 18496 bytes
SHA-256: e48c0bb7ceffaae7f470c7bb190ced316ac7427fae9ad55b858f662a7463638b
font_01_sfnt_off000103ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103BA 10700 bytes
SHA-256: 1e174d2ed35b34663da1a72b1fb0dd8f64e8ad1a2435d6e7527bc65aff25ab93
font_02_sfnt_off00011c47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C47 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1