Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f37292f311d0016…

MALICIOUS

PDF

74.8 KB Created: 2021-09-09 08:21:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: c1b3a030e25fb0d513dfd6ba21094ade SHA-1: 158f69f84899ae66c35155997e3df3f1c9e056db SHA-256: 8f37292f311d00161721a18269639eb01e8e6db2d3ef0982dd8d8bc6cafa4333
142 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, with heuristics indicating embedded JavaScript and a link farm structure. The presence of a 'download button' lure and numerous external URLs suggests an attempt to trick the user into downloading a malicious payload or visiting a phishing site. The embedded JavaScript is likely responsible for initiating the malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://uzks.hr/upload/datoteke/60863500319.pdf In PDF document text
    • https://www.southdownscellars.co.uk/ckfinder/userfiles/files/fusaluvafixegarapop.pdfIn PDF document text
    • http://mayepnuocmia.vn/data/ckfinder/files/66427519912.pdfIn PDF document text
    • http://sincaremedicaltour.com/js/upload/59005428823.pdfIn PDF document text
    • http://ytbozhuo.com/upload/file/011345091755.pdfIn PDF document text
    • https://xn--fiqa735be48e.com/upload/files/25201433612.pdfIn PDF document text
    • https://haciendaloscipreses.cl/upload/file/gawujimipagibomomiw.pdfIn PDF document text
    • https://vietrocknet.org/app/webroot/img/files/35835194857.pdfIn PDF document text
    • http://gomientrung.vn/uploads/image/files/tevuxerizu.pdfIn PDF document text
    • https://zilalcooling.com/other_files/File/jizijojumofogixa.pdfIn PDF document text
    • https://akrmedia.no/ckfinder/userfiles/files/15697096385.pdfIn PDF document text
    • http://faithleader.org/js/ckfinder/userfiles/files/7460289008.pdfIn PDF document text
    • http://northmarking.com/userfiles/files/xedagevivuvelupijasosed.pdfIn PDF document text
    • http://suchanekstomatolog.pl/files/file/nidipe.pdfIn PDF document text
    • https://pierreseche.fr/userfiles/file/48745040744.pdfIn PDF document text
    • https://brihat-group.com/assets/userfiles/files/tekimin.pdfIn PDF document text
    • https://mlbcsimleague.com/ckfinder/userfiles/files/dosobefobomazuretemep.pdfIn PDF document text
    • https://www.thaiahpa.com/flash/files/60065268537.pdfIn PDF document text
    • http://burragebrothers.org/demo/jolie/beta/userfiles/files/nulizaxobowemuzodixadafal.pdfIn PDF document text
    • http://apisicul.com/userfiles/files/vosavelelekotiba.pdfIn PDF document text
    • http://luisacortesearchitetto.it/userfiles/files/94305215877.pdfIn PDF document text
    • http://pillshop.ru/uimg/files/25412656947.pdfIn PDF document text
    • http://clean-ecology.com/Upload/files/3315509078.pdfIn PDF document text
    • https://epponline.com/mentorfinancial/page_images/file/22394247733.pdfIn PDF document text
    • http://brezov-gaj.si/uporabnik/file/37126201495.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=best+android+app+for+recovering+deleted+filesPDF 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_off0000c164.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC164 10916 bytes
SHA-256: 02d63d0c370d08cf6024936a052a51e25fd69694a60e748e8e4799208054aa55
font_01_sfnt_off0000daa1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAA1 16772 bytes
SHA-256: 1a2bf4fb61489c3b127eb63607086688ce6883ebf3fed4999a1bce956c779df2
font_02_sfnt_off0001054d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1054D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1