Malicious PDF — malware analysis report

Static analysis result for SHA-256 7afa19977c70d9bb…

MALICIOUS

PDF

79.0 KB Created: 2021-09-23 07:07:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 6292c297d3086426deff49061f2764b0 SHA-1: 35831d56ffac5f952ceb2ea154dea9f2dc064c5c SHA-256: 7afa19977c70d9bbcaeb4d12d43b258df546c2f63e087cb69f117228222a469a
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The presence of numerous external URIs, many pointing to disposable hosting and acting as link farms, suggests a phishing or malware distribution scheme. The document body is heavily obfuscated, preventing a clear understanding of its direct content, but the overall structure and heuristic firings strongly indicate a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://pistant.ru/uplcv?utm_term=seven+brief+lessons+on+physics+pdf+free PDF link annotation
    • http://wellfoto.cz/pictures/files/75644169471.pdfIn PDF document text
    • http://mibenjamin.com/userfiles/file/gazawoxesixatapanukojaton.pdfIn PDF document text
    • http://faizleathergloves.com/userfiles/files/67380110623.pdfIn PDF document text
    • http://ciaomamma.hu/editor_up/ziguvujade.pdfIn PDF document text
    • https://devcons.org/uploads/userfiles/files/13450658215.pdfIn PDF document text
    • https://lexcochoralsoc.org/demo/lccs/beta/userfiles/files/96818383482.pdfIn PDF document text
    • http://ityab.com/cache/fck_files/file/sinonun.pdfIn PDF document text
    • http://terezszilvia.com/images/uploaded/file/851708403.pdfIn PDF document text
    • http://udaybharat.in/ckfinder/userfiles/files/pixijosalazegewenojenidur.pdfIn PDF document text
    • http://innovad-ltd.com/userfiles/file/lipetilul.pdfIn PDF document text
    • http://naphogacomposite.com/upload/files/bepevarexugezufen.pdfIn PDF document text
    • https://xn--pssa17sw71b.tw/upimages/files/22988636955.pdfIn PDF document text
    • http://clinicaveterinariagoitese.it/userfiles/files/giroxe.pdfIn PDF document text
    • http://nature-revive.org/files/file/84734866869.pdfIn PDF document text
    • http://xn--c1ajalgzu0a.xn--p1ai/userfiles/file/lemafejolivul.pdfIn PDF document text
    • https://arendic.cl/files/6129328381.pdfIn PDF document text
    • http://jfhcoaching.nl/userfiles/files/gojosu.pdfIn PDF document text
    • http://asdgolfclubtoscana.com/writable/public/userfiles/file/98927254438.pdfIn PDF document text
    • http://hanasushichoice.com/uploads/files/girelogotazabuv.pdfIn PDF document text
    • http://hkparkkonutlari.com/image/files/39188053992.pdfIn PDF document text
    • https://giorgiosantinelli.it/file/94564204704.pdfIn PDF document text
    • http://pamatudarbai.lt/ckfinder/userfiles/files/77061113861.pdfIn PDF document text
    • http://kbinteriery.cz/userfiles/file/novar.pdfIn PDF document text
    • https://chuyennhakienvangvn.net/upload/files/foboberarixufofixolopovo.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_off0000cda5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDA5 10852 bytes
SHA-256: f9b045c3f7e0243085b87d69f0258c631e7e9bc9bc22db00d98d0b41dd61b10e
font_01_sfnt_off0000e665.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE665 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fe77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE77 18564 bytes
SHA-256: 3e4253c43f199bddada7d170aadaf918097ff35f06dd03413167a7745b3c3573