Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1f9757ad31628e7…

MALICIOUS

PDF

77.0 KB Created: 2021-09-28 00:28:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: ab723ad21699fa5c043bc6ad8ba01c36 SHA-1: 2e30ebaa43316f237493c9f7947a591ff6d35bf7 SHA-256: b1f9757ad31628e7884387881e5323bc6f751e619d4252d60ce7c6913b24dfc1
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The sample was classified as malicious by a machine learning model and ClamAV, indicating a high likelihood of malicious intent. Heuristics identified it as a PDF link farm with numerous external URIs hosted on disposable domains, suggesting a phishing or malware distribution scheme. The embedded URLs are the primary indicators of compromise, likely leading to further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://coretry.ru/uplcv?utm_term=android+rom+creator PDF link annotation
    • http://lblussana.it/images/file/1992118138.pdfIn PDF document text
    • https://hoongnau.com/upload/files/41213173824.pdfIn PDF document text
    • https://hunde-katzen.at/soubory/zenawop.pdfIn PDF document text
    • https://korvioinfotech.com/ckfinder/userfiles/files/berodolilokitabemi.pdfIn PDF document text
    • https://sidexsideaudio.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131bc8c76fd7---60565026060.pdfIn PDF document text
    • http://odessawa.com/userfiles/file/zagetozigaganij.pdfIn PDF document text
    • http://studiobaldizzone.com/userfiles/files/40753519934.pdfIn PDF document text
    • http://aqgwegfjdlk.handyfriendship.com/upload/files/70609076106.pdfIn PDF document text
    • http://saktigroup.in/uploads/68119918733.pdfIn PDF document text
    • https://truonggiangcompany.com/userfiles/file/58901243056.pdfIn PDF document text
    • https://justforjetscatering.com/userfiles/image/files/78537678272.pdfIn PDF document text
    • http://kaupa.cz/userfiles/file/51270664554.pdfIn PDF document text
    • http://charolais-hessen.de/write/userfiles/file/furidemokigimosomov.pdfIn PDF document text
    • http://ettermanenterprises.com/ckfinder/userfiles/files/dutowali.pdfIn PDF document text
    • https://kultmotor.hu/images/files/jewirufofetusinulura.pdfIn PDF document text
    • http://kolbiko.com/images/uploads/file/wejesifuxefisudoboletiku.pdfIn PDF document text
    • https://www.educazionesessuale-scuola.ch/ck/ckfinder/userfiles/files/11981890196.pdfIn PDF document text
    • https://bi-kiesabbau.de/cmsimple/images/file/75706729615.pdfIn PDF document text
    • https://apexsafetyproducts.com/ckfinder/userfiles/files/wojibex.pdfIn PDF document text
    • https://perfecthospital.org/FCKeditor/file/9585796727.pdfIn PDF document text
    • http://eros-arena-reutlingen.de/eros/userfiles/file/sadebete.pdfIn PDF document text
    • http://mecateengenharia.com.br/ckfinder/userfiles/files/zaguju.pdfIn PDF document text
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614e78e05886b---26075341.pdfIn PDF document text
    • http://z500.si/files/26985261655.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_off0000c153.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC153 20636 bytes
SHA-256: 76f25df88db64e13dc0e6c9a8d1638a64e17e9456f20f579f4b3c64f23d1c8ed
font_01_sfnt_off0000f76b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF76B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010f82.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F82 10296 bytes
SHA-256: b92527c990efc6d0b0906cb926876ef5a1519ef26c2d2e509169db168bd66e69