Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac966e37c86d3373…

MALICIOUS

PDF

72.4 KB Created: 2021-10-08 02:54:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 3359a4fb3b879451d19505dbd865713c SHA-1: 8e23ade0f2afcffc21cc8a26e368e46d9479c274 SHA-256: ac966e37c86d3373a198b6479579420570d9621a6989fe360881a69fa22ca9ea
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external URLs, with one specifically identified as part of a link farm on disposable hosting, suggesting a phishing or redirection scheme. The PDF structure and embedded URLs point towards an attempt to direct users to potentially harmful external content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9915

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://queure.ru/uplcv?utm_term=sexual+questions+and+answers PDF link annotation
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/1615b0ce51043d---ruzipatuvozex.pdfIn PDF document text
    • http://zvezda-rostov.ru/ckfinder/userfiles/files/48103860952.pdfIn PDF document text
    • https://masihpt1.com/contents/files/ruxubam.pdfIn PDF document text
    • http://perevodvnegiloifond.ru/pict/file/56162720837.pdfIn PDF document text
    • http://cafecontinentalmd.com/uploads/files/2877156833.pdfIn PDF document text
    • http://ugrctrani.it/userfiles/files/latoboketidepobuk.pdfIn PDF document text
    • http://studiolorenzino.eu/userfiles/files/361696796.pdfIn PDF document text
    • http://fuhua.tumujike.com/assets/upload/files/202109111544472673.pdfIn PDF document text
    • https://endobible.com/userfiles/file/mejofovug.pdfIn PDF document text
    • http://noithatphathuy.com/Images_upload/files/gipasogepatewepari.pdfIn PDF document text
    • http://www.smwiarus.pl/ckfinder/userfiles/files/49620840410.pdfIn PDF document text
    • http://lignumweb.com/site/webroot/uploads/files/36019753847.pdfIn PDF document text
    • http://kemenyseprosiklos.hu/upload/file/8682050787.pdfIn PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1613ab56679358---4771050711.pdfIn PDF document text
    • http://taiwan-casters.com/userfiles/file/93232256736.pdfIn PDF document text
    • https://theipbuzz.com/images/file/8857096780.pdfIn PDF document text
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614467f9ce8d3---jomemabuw.pdfIn PDF document text
    • http://regimhotelierbucuresti.com/images/userfiles/4021876643.pdfIn PDF document text
    • http://bjxbw.cn/userfiles/file/96906148767.pdfIn PDF document text
    • http://shangrilayunnan.com/ckfinder/userfiles/files/dumat.pdfIn PDF document text
    • http://myjobcareer.net/userfiles/file/2021091121324573499.pdfIn PDF document text
    • http://ch-bovi.com/upload/files/47001268944.pdfIn PDF document text
    • http://yacpa.org/yacpafiles/file/kobif.pdfIn PDF document text
    • http://seed-hongkong.com/uploads/file/34696987399.pdfIn PDF document text
    • http://xsteelstock.com/d/files/rebifupivif.pdfIn PDF document text
    • http://yomamasushitogo.com/uploads/files/ximawa.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_off0000b8fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8FB 10748 bytes
SHA-256: c069e6264205d503dfcd4722cc8de17cbb718ed0749de4f5544f74b133f135b3
font_01_sfnt_off0000d1ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1AB 15984 bytes
SHA-256: f3bcb851e66526ce33174665f0057dfb5c0875b94381307aad8fdfa6daf94fda
font_02_sfnt_off0000fa41.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA41 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1