Malicious PDF — malware analysis report

Static analysis result for SHA-256 c1f7f1547111ff3f…

MALICIOUS

PDF

70.9 KB Created: 2021-09-21 00:30:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 535668cdc88647fe6702dd5e2fa82dcb SHA-1: c22121b6e38046adc466412f063d7456b9787dc6 SHA-256: c1f7f1547111ff3f33bf53470e0da4a3aac82861d5e432e5083b9dcb2cc61797
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external URLs, with heuristics suggesting it functions as a link farm on disposable hosting, likely to redirect users to phishing or malware download sites. The presence of embedded URLs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic strongly support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9909

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://queure.ru/uplcv?utm_term=pillow+thoughts+download+pdf PDF link annotation
    • https://pingthye.com/userfiles/files/potedubidevixelo.pdfIn PDF document text
    • http://koreadramatour.com/FileData/ckfinder/files/20210908_61B4A2A5F1A67401.pdfIn PDF document text
    • http://modernplating.com/userfiles/file/gutufowal.pdfIn PDF document text
    • http://www.offshoreyachts.net/web_upload/editor/files/96249708601.pdfIn PDF document text
    • http://instit.ac/ckfinder/userfiles/files/tufevineworawe.pdfIn PDF document text
    • https://ud-hobby.com/images/Upload/file/xogabakevizusixu.pdfIn PDF document text
    • http://cocoon-source-harmonie.fr/public/file/20911025211.pdfIn PDF document text
    • http://mutitar.com/user_img/files/purizemuxalitexaxivuxaj.pdfIn PDF document text
    • http://maginsaatmetal.com/resimlerfiles/pazimifutorufizos.pdfIn PDF document text
    • http://nwatchonline.info/userfiles/file/vubikebelikatab.pdfIn PDF document text
    • http://global-poseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/161424b3217601---fiwan.pdfIn PDF document text
    • http://ashole.hu/UserFiles/File/givapozijidesiw.pdfIn PDF document text
    • https://khotelmarket.com/FileData/ckfinder/files/20210914_63BA4ED34674AE8D.pdfIn PDF document text
    • http://gaudi.tw/upload/file/51058279560.pdfIn PDF document text
    • http://avalon-essenzen.at/userfiles/file/komuminojirukikuwijalaj.pdfIn PDF document text
    • http://weilandvloeren.nl/fckimages/bukorulugiri.pdfIn PDF document text
    • http://mgocsm.in/userfiles/file/xogomarasatuvijeriso.pdfIn PDF document text
    • https://keluargamimpi.com/contents/files/90527144390.pdfIn PDF document text
    • https://www.acta-mobilier.fr/ckfinder/userfiles/files/43231783361.pdfIn PDF document text
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/f8869268c78714a6d92aee749a15fe70/digofipokobaximufifatujak.pdfIn PDF document text
    • https://lazdynumokykla.lt/userfiles/file/pegazor.pdfIn PDF document text
    • http://salocchi.it/userfiles/files/33173213314.pdfIn PDF document text
    • http://asremajazi.com/uploads/files/duduvigazesexo.pdfIn PDF document text
    • http://hanyuchina.com/upload/files/wodawelasodudamarubig.pdfIn PDF document text
    • http://synergytaekwondo.com/click2buy_newp/userfiles/file/51865325727.pdfIn PDF document text
    • http://huucodatlanh.com/userfiles/file/levarogubapupuvamezim.pdfIn PDF document text
    • http://phutungototuanphat.com/img-tvdl/files/63562171826.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_off0000b875.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB875 14616 bytes
SHA-256: f251978a8efc867938d5ce8314b20d6f393b8fb3692d7e40c3c6a47d963e2008
font_01_sfnt_off0000dd42.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD42 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f559.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF559 10732 bytes
SHA-256: b52c9d2378e165c14a2c7227ea0d8ad844c293b499ce7c8e8dd2739e91e40c27