Malicious PDF — malware analysis report

Static analysis result for SHA-256 bcaaa14a964361f5…

MALICIOUS

PDF

75.3 KB Created: 2021-09-12 01:05:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 695e1abce4b963f8040760266d2350d5 SHA-1: 585c128eddd58772e1dec28885c5b9c2d9555d46 SHA-256: bcaaa14a964361f5e76aa30d42dd9fa8aee50c8eef5451f7e951c33c1a9970a0
174 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate the presence of external URIs and a link farm, along with a lure to install a browser extension or update. These findings suggest a social-engineering attack aimed at tricking the user into downloading and executing further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://crysiq.ru/uplcv?utm_term=american+english+file+placement+test+pdf PDF link annotation
    • http://bm-shower.com/userfiles/files/saxatejodijiwi.pdfIn PDF document text
    • https://guruamardaspublicschool.com/userfiles/files/moluradijugumivena.pdfIn PDF document text
    • https://thietbidiensino.vn/media/ftp/file/fepagifo.pdfIn PDF document text
    • http://lltsg.com/uploadfile/file///2021091013115094.pdfIn PDF document text
    • https://notofthisgalaxy.com/wp-content/plugins/super-forms/uploads/php/files/j38ukft5at4342og39dftut2fn/78861635392.pdfIn PDF document text
    • http://debten.net/UserFiles/File/pujekifejoxokowonub.pdfIn PDF document text
    • https://hkfew.org.hk/ckfinder/userfiles/files/xokojo.pdfIn PDF document text
    • https://lengthening-sldf.com/userfiles/file/42574048418.pdfIn PDF document text
    • https://digireg.nz/upload/68406306111.pdfIn PDF document text
    • http://nabisori.com/userfiles/file/wetebogarozidovefubu.pdfIn PDF document text
    • http://zezoalza.com/ckupload/files/46233427631.pdfIn PDF document text
    • https://fortworthdental.net/cmsCart/upload/file/pawepuniza.pdfIn PDF document text
    • http://costruzionibulagna.it/userfiles/files/87478201726.pdfIn PDF document text
    • https://cmottaviproductive.it/uploads/file/62270711850.pdfIn PDF document text
    • http://s13cf5ef.alojamientovirtual.com/ropalaboralbarata.com/userfiles/file/xetigixanowamobi.pdfIn PDF document text
    • http://pkpneu.cz/userfiles/file/xotobaribazerarexexeva.pdfIn PDF document text
    • https://vaynhanh365.net/contents/files/zegipezijugoj.pdfIn PDF document text
    • http://macierz-grodziec.org/files/file/fexudono.pdfIn PDF document text
    • http://annassteen.com/ckfinder/userfiles/files/44804092202.pdfIn PDF document text
    • https://rrvchefs.com/wp-content/plugins/super-forms/uploads/php/files/2299292edcc9feaa737e5d44473ab6d7/969505128.pdfIn PDF document text
    • https://www.solucionaesp.com/ckfinder/userfiles/files/dixakitakagopavivemibeni.pdfIn PDF document text
    • http://strahovka66.ru/userfiles/file/vetaxafoxilipafapupo.pdfIn PDF document text
    • http://harekatmemuru.com/images/Media/files/26580237317.pdfIn PDF document text
    • http://hoteldanang.com/uploads/images/files/96815125101.pdfIn PDF document text
    • http://chinhlytailieuluutru.com/media/ftp/file/zewajepuritawalaf.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_off0000c03a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC03A 10928 bytes
SHA-256: eefe745516eaebe7986d48b6db47028a293df862a08dcc76fa816be053208d8b
font_01_sfnt_off0000d912.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD912 18372 bytes
SHA-256: 5ad002ee96fe8bdddffb05bc21414126e990d085218e7869b8c9b526005dc29b
font_02_sfnt_off00010793.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10793 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1