Malicious PDF — malware analysis report

Static analysis result for SHA-256 33402bb6abc7a14c…

MALICIOUS

PDF

88.3 KB Created: 2021-09-13 18:52:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 2912d8c6a851752ed390fc94703c0dd9 SHA-1: e06bf09d200eb71411924e3324d3ba94117ba704 SHA-256: 33402bb6abc7a14c7db82f4a3a8fd9ce7500fcea3876f275fe12d26a69a4f945
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a high-confidence ML classifier and ClamAV detection as a phishing trojan. The presence of numerous external URIs, many pointing to PDF files on disposable hosting, strongly suggests a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, indicating it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://medvor.ru/uplcv?utm_term=loco+play+games+and+earn+money PDF link annotation
    • https://butagallery.com/userfiles/files/jarujolitojix.pdfIn PDF document text
    • http://garankuccu.com/upload/fckimagesfile/58fecbc332cd7e91c103889444cbe395.pdfIn PDF document text
    • http://rsentco.com/upload/file/jutagijopotiwubujodadevi.pdfIn PDF document text
    • http://veterinariacasettamattei.it/userfiles/files/53659418511.pdfIn PDF document text
    • http://youzedu.com/ckimages/files/20210911100735721249.pdfIn PDF document text
    • http://compsult.net/userfiles/file/xizosopu.pdfIn PDF document text
    • https://ceadersvalet.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c2295af85f---vakegowupa.pdfIn PDF document text
    • https://epagneuls-bretons.fr/caningest/images/file/vinesodosaxavakoxe.pdfIn PDF document text
    • http://waycreon.net/bhaskar/yii/upload/files/24477845991.pdfIn PDF document text
    • http://food-cloud.com/home/food-cloud/www/site/site/data/files/59009699615.pdfIn PDF document text
    • https://riwg.in/userfiles/file/semasitogad.pdfIn PDF document text
    • http://wwpokebar.com/uploads/files/40464813287.pdfIn PDF document text
    • https://study-abroad-travel.com/ckfinder/userfiles/file/3805273174.pdfIn PDF document text
    • http://shippingengineering.com/files/ckeditorothers/jitakupavulopemudaxevo.pdfIn PDF document text
    • https://holocaustresearch.pl/nowy/photo/file/zeriziribuku.pdfIn PDF document text
    • https://grahampropertytax.com/wp-content/plugins/super-forms/uploads/php/files/d39cc1c942c755da2b870a30ffaa3f8d/32473253602.pdfIn PDF document text
    • http://xiangzhuan.tw/upload/files/31967622755.pdfIn PDF document text
    • http://toyotarent.tw/FileData/ckfinder/files/20210902_BCD9ACACABB9469A.pdfIn PDF document text
    • https://theelementrama9.com/userfiles/files/15192778466.pdfIn PDF document text
    • https://oncallanatomist.org/ckfinder/userfiles/files/39932572950.pdfIn PDF document text
    • http://brmhn.com/userfiles/file/20210913004543_2mdgoo.pdfIn PDF document text
    • http://nanopena.cz/upload/file/nojipulesoded.pdfIn PDF document text
    • https://capecoralliving.com/media/file/88814124445.pdfIn PDF document text
    • http://sipzip.com/userfiles/file/vegukatitaduvofito.pdfIn PDF document text
    • https://icicle-mountaineering.ltd.uk/ckfinder/userfiles/files/vozitugumada.pdfIn PDF document text
    • http://webbyshoe.com/fckeditor/userfiles/file/jaziromaxukis.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_off0000f286.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF286 10740 bytes
SHA-256: ac6c0e8b062c6ddf815ef3f4e1453fed65952a9f53c41bcd5e9e5e5e65c2a556
font_01_sfnt_off00010afa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AFA 17756 bytes
SHA-256: 94d2e77131376361be735514fc28a3794527e896ac85f383e8893d988e7a4a57
font_02_sfnt_off00013982.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13982 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1