Malicious PDF — malware analysis report

Static analysis result for SHA-256 d4437980a076a958…

MALICIOUS

PDF

70.2 KB Created: 2021-09-16 18:01:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 0df7849b94ad65d3fa163f51816bb67b SHA-1: 757c2bfc75ee2ec6b0deca1be264e300a93279c7 SHA-256: d4437980a076a9581d03ebe36b4e83cf2d3620c8aecbcad44ec4b6d8d74da143
174 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains embedded JavaScript and numerous external links, many hosted on disposable domains, suggesting it's designed to lure users to phishing sites or download further malicious content. The PDF_RANDOM_URL_LINK heuristic specifically points to a link to an algorithmically-generated URL, reinforcing the malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • 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://allytemp.ru/uplcv?utm_term=happy+chick+apk+download+old+version PDF link annotation
    • https://combrooncom.com/contents/files/801829487.pdfIn PDF document text
    • http://claudiamelchior.it/images/file/jekasafexilifu.pdfIn PDF document text
    • https://cantellodetersiviprofessionali.it/uploads/file/70425724833.pdfIn PDF document text
    • http://sbstroy53.ru/img/files/sajusefupasinajibuwome.pdfIn PDF document text
    • http://www.barbazan-debat.fr/ckfinder/userfiles/files/66456344560.pdfIn PDF document text
    • http://www.aceitunasdelguadalhorce.es/ckfinder/userfiles/files/nuwovaveburodivujud.pdfIn PDF document text
    • http://vit-physio.de/file/tenubexulunenof.pdfIn PDF document text
    • http://dreamwith.gni.kr/ckupload/files/sebidasakokikigukez.pdfIn PDF document text
    • http://boschvietnam.com/files/usersfiles/files/7952365414.pdfIn PDF document text
    • https://ka-base.no/images_students/files/begatufagi.pdfIn PDF document text
    • https://dalilak1.com/userfiles/file/fogupujatifilefexug.pdfIn PDF document text
    • http://www.erealitysolutions.com/tennisontario/assets/appsadmin/js/ckfinder/userfiles/files/kimofiderolamopemo.pdfIn PDF document text
    • http://amako-ra.com/wp-content/plugins/super-forms/uploads/php/files/a693bf5065ed8dbecc730ab74e7de5d4/pudoparilibafubotir.pdfIn PDF document text
    • https://northwestconvention.cz/data/files/sopituxabogopelidet.pdfIn PDF document text
    • https://munis-roquesalbes.cat/demo/vilalba/imatges/file/32792067494.pdfIn PDF document text
    • http://professional-tuner.at/uploaded/file/15748335492.pdfIn PDF document text
    • http://stavebnevyrobky.sk/www/upload/files/27732170759.pdfIn PDF document text
    • http://allprintusa.com/admin/images/file/lotomogovavabusafupu.pdfIn PDF document text
    • https://livermore.com/wysiwygfiles/file/lakenajepe.pdfIn PDF document text
    • http://cerritos.songhakbbq.com/uploads/files/kijapikirezumixizimit.pdfIn PDF document text
    • http://gk-eventus.ru/admin/ckfinder/userfiles/files/72206858416.pdfIn PDF document text
    • http://vinhomeshaiphong.net/app/webroot/img/files/50361668117.pdfIn PDF document text
    • https://saikekanglun.com/filespath/files/20210914084955.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_off0000b1eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1EB 15252 bytes
SHA-256: e11bdb145775be7ff1b0a0e1a7508286bc4b7930ec4d6593ddcbab120975d129
font_01_sfnt_off0000d834.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD834 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f04b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF04B 10860 bytes
SHA-256: ae42ed541b003aa33e4c46daf6c83ad1e9f2adc010a23bae9700261184b7947f