Malicious PDF — malware analysis report

Static analysis result for SHA-256 8498d99e3b28aa5a…

MALICIOUS

PDF

71.0 KB Created: 2021-10-07 11:14:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 765040d1731d01d884791bddb08b326a SHA-1: 861eb06e83f189aebd18687268f3e1cffd032d18 SHA-256: 8498d99e3b28aa5adea2724a0856e13b58ef12df6fc7d7aef4558f93cc18726a
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URLs, indicating a phishing or redirection attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The presence of malformed streams and link farm characteristics further support this assessment, pointing towards a spearphishing attachment delivery vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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://garglob.ru/uplcv?utm_term=parts+of+a+front+page+newspaper PDF link annotation
    • http://otvorene-srdce.sk/userfiles/file/53855358278.pdfIn PDF document text
    • http://rsti.biz/files/fck/file/vugosixuvujefibalefamer.pdfIn PDF document text
    • https://toppelletmachine.com/d/files/petijadidota.pdfIn PDF document text
    • https://tepatsasaran.com/contents/files/10628573879.pdfIn PDF document text
    • https://vnycc.com/userfiles/file/rogotefewupuzu.pdfIn PDF document text
    • https://michaels-limo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614d804de16bd---jufajawuxoxogi.pdfIn PDF document text
    • https://reazfarah.com/ckfinder/userfiles/files/zesujagudilubovowexilaza.pdfIn PDF document text
    • http://churchtextile.com/userfiles/file/lopaxenarefonolesumeduna.pdfIn PDF document text
    • https://priscar.com/documents/files/14677392292.pdfIn PDF document text
    • http://mywayrtk.org/userfiles/file/42258165032.pdfIn PDF document text
    • http://zensushialiso.com/uploads/files/zavolajuviruvuga.pdfIn PDF document text
    • https://stvorki.ru/files/file/76044666639.pdfIn PDF document text
    • https://aykutemlak.com/upload/ckfinder/files/tepufawiredajevokokekiv.pdfIn PDF document text
    • http://galluccifaibano.com/userfiles/file/40488628949.pdfIn PDF document text
    • http://www.pethouse.es/ckfinder/userfiles/files/ponajusapadevotuvobezato.pdfIn PDF document text
    • http://kfoodntea.com/dataroom/file/lizesuriw.pdfIn PDF document text
    • https://royal-art.pl/uploads/userfiles/files/sudekex.pdfIn PDF document text
    • http://trustarshida.co/cache/fck_files/file/wuwijozigijutofow.pdfIn PDF document text
    • http://buyo-g.net/userfiles/file/wewemojilot.pdfIn PDF document text
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614166ed84ae7---69619340024.pdfIn PDF document text
    • http://areopag-group.ru/sites/default/files/uploads/vilomaledujibugametaxoki.pdfIn PDF document text
    • https://www.eecpowerindia.com/codelibrary/ckeditor/ckfinder/userfiles/files/naxixijetirerofotomeb.pdfIn PDF document text
    • http://duancanhotot.com/upload/files/pupudap.pdfIn PDF document text
    • http://moje-stranky.eu/userfiles/file/11309782180.pdfIn PDF document text
    • http://cuacuongiare.vn/upload/files/53471480787.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_off0000b687.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB687 10484 bytes
SHA-256: d37b6d401553a0029a8f35027cf7bc9be09c5472ef05dfc1f086df7f83256f1a
font_01_sfnt_off0000ce98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE98 15868 bytes
SHA-256: db3e2ec99868979236b46b0439b0ce3ea26a6eb6153c15d1bbe4db81ad6d543e
font_02_sfnt_off0000f682.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF682 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1