Malicious PDF — malware analysis report

Static analysis result for SHA-256 55310d881603e4f9…

MALICIOUS

PDF

71.8 KB Created: 2021-09-27 11:18:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: a05c966ed624c202db5e889b69e394cd SHA-1: 6dfefcbdd617b3281916b1cfe6ebffc4a799a495 SHA-256: 55310d881603e4f9d525e5cbfbc6973cb3abe8da39bb04aeb842085bb8d5be7d
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file containing embedded JavaScript, which is a common technique for executing malicious code. It also features a link farm with numerous URLs, many pointing to compromised CMS upload directories, suggesting an attempt to host or distribute malicious content. The primary lure appears to be related to checking Instagram account viewers, a common social engineering tactic.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9837

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://pixomot.ru/uplcv?utm_term=how+to+check+who+viewed+your+instagram+account PDF link annotation
    • http://rabotatver.ru/userfiles/admin/nezora.pdfIn PDF document text
    • https://deltaguvenlik.net/userfiles/file/78230429666.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/16146eb8fc81e2---18381941742.pdfIn PDF document text
    • https://teplitsyoptom.ru/wp-content/plugins/super-forms/uploads/php/files/f59cba3b2f3e35d1463ed681eac79bbc/pozofasanozetobafiginav.pdfIn PDF document text
    • https://alcoolassistance-creuse.net/www/site/js/ckfinder/userfiles/files/wajirogidodosatowusuj.pdfIn PDF document text
    • http://accessiblevehicleservices.com/userfiles/file/62631508271.pdfIn PDF document text
    • http://feg.vn/uploads/files/tuluxekuzinama.pdfIn PDF document text
    • https://majubesar.org/contents/files/vafepegunugi.pdfIn PDF document text
    • http://vers-ma.de/userfiles/file/gufaturavo.pdfIn PDF document text
    • https://antoinepanau.com/wp-content/plugins/super-forms/uploads/php/files/de014775b63fb71b3020081e4e2c492a/dimenuvi.pdfIn PDF document text
    • http://gokea.org/upload/editor/files/53877932804.pdfIn PDF document text
    • http://exima.kr/userData/board/file/butiwedi.pdfIn PDF document text
    • http://dabaizhongxue.com/upload_fck/file/2021-9-18/20210918151839308119.pdfIn PDF document text
    • http://crestviewshopping.abwingsmd.com/uploads/files/razezaniwawog.pdfIn PDF document text
    • http://tandartsindex.nl/images/uploads/dimapefiruduxurotok.pdfIn PDF document text
    • https://charteriraq.ir/basefile/charteriraqir/files/zatisigetodalug.pdfIn PDF document text
    • http://florylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/27861096243.pdfIn PDF document text
    • https://edenestates.com/ckfinder/userfiles/files/13211828618.pdfIn PDF document text
    • http://happinessgown.com/upload/users/files/vufuxugusad.pdfIn PDF document text
    • http://davcpundri.com/css/file/samuziretugojudujepap.pdfIn PDF document text
    • http://nenorm.com/files/files/70307056782.pdfIn PDF document text
    • https://www.indee-r.fr/wp-content/plugins/super-forms/uploads/php/files/c3bee108c6c4bdfcc5b07d1cdae389d6/joripafasolasogonebusat.pdfIn PDF document text
    • https://lazerom.pro/media/file/xetarili.pdfIn PDF document text
    • http://zamaro.cz/images/fcke_files/file/vokilowumuwufofibukudop.pdfIn PDF document text
    • http://krakow4you.pl/krakow/files/vererom.pdfIn PDF document text
    • http://ottomaniantextile.com/userfiles/file/83136740936.pdfIn PDF document text
    • http://etalentlink.com/uploadfile/file///2021090312123728.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_off0000b55b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB55B 11220 bytes
SHA-256: 0c8c80df58bf922b184a08c96fd17cd712e2ed073f464a8ba7e57baeddae443e
font_01_sfnt_off0000cf54.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF54 16620 bytes
SHA-256: b687d6e34b6f1f2c0ce3ffd3b6ffe16163d1a67852769991461803d679700a31
font_02_sfnt_off0000f91b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF91B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1