Malicious PDF — malware analysis report

Static analysis result for SHA-256 7b41d1518bc8f6f8…

MALICIOUS

PDF

90.3 KB Created: 2021-09-13 03:23:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 5949e1044f44420eadb1ee96b86a1da8 SHA-1: e13d7f965e3634d44bdeae5b42db5bc2c1d104e7 SHA-256: 7b41d1518bc8f6f81fb8fe6072f56ee0b609e3c0f870589d98cbb830b88b8e81
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many pointing to disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a deliberate attempt to create a large number of links on low-reputation domains, suggesting a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly support the malicious nature of this file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

Heuristics 6

  • 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.
  • 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://smidgel.ru/uplcv?utm_term=chrome+dark+space PDF link annotation
    • http://www.gpkoaee.ru/ckfinder/userfiles/files/57671761051.pdfIn PDF document text
    • https://imahima.xyz/js/ckfinder/userfiles/files/41214229275.pdfIn PDF document text
    • https://xn--90ah6akb9e.xn--p1ai/f/file/savoneju.pdfIn PDF document text
    • http://www.1atlanticfunding.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b1ae409295---31261862156.pdfIn PDF document text
    • http://www.ciesol.es/ckfinder/userfiles/files/97621224626.pdfIn PDF document text
    • http://friulanapanini.com/images/file/41588605.pdfIn PDF document text
    • http://www.me.ntou.edu.tw/ckfinder/userfiles/files/20210901_171115.pdfIn PDF document text
    • http://ggmtc.net/userfiles/files/81337693992.pdfIn PDF document text
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/aj7sfon614l4hkh67hl4j0avph/falegojefabedodimanajaval.pdfIn PDF document text
    • https://granitnet.hu/editor_up/79483370040.pdfIn PDF document text
    • http://gz-chengeng.com/uploadfile/files/lebapilenaborodewera.pdfIn PDF document text
    • https://ustunbilgisayar.com/userfiles/files/mozizozunagusuveka.pdfIn PDF document text
    • https://shopexpert.com/app/webroot/files/userfiles/files/57045145458.pdfIn PDF document text
    • http://edisonprivateschoolbeta.com/cote_dor_import/admin/ckfinder/userfiles/files/16419601866.pdfIn PDF document text
    • https://svetplus.com/userfiles/files/40653889988.pdfIn PDF document text
    • http://sochi-polyana.com/ckfinder/userfiles/files/dugufemozotiputamizuru.pdfIn PDF document text
    • https://parc-hotel.info/file/6729467816.pdfIn PDF document text
    • https://atavio.ru/files/file/topivunifus.pdfIn PDF document text
    • http://karinameal.com/imgdish/files/75243265997.pdfIn PDF document text
    • http://wsmr.us/userfiles/file/bamazuxilagixofuwineset.pdfIn PDF document text
    • http://mc-opony.pl/files/file/logefatikotibaduzeji.pdfIn PDF document text
    • http://ser-buk.com/userfiles/file/laxovivap.pdfIn PDF document text
    • http://knowleangling.co.uk/ckfinder/userfiles/files/pixupivekibeborawamirexe.pdfIn PDF document text
    • http://air-ned.com/uploads/files/junixux.pdfIn PDF document text
    • http://provia-events.de/pics/fotos/1/file/34956212173.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_off0000fe12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE12 17444 bytes
SHA-256: aef9d758b7a05a85244f855ef0624d051ee8bb177d27c47faad298ede1f5079a
font_01_sfnt_off00012b2b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B2B 10564 bytes
SHA-256: 3db18ef1bfc9c26f11fbfead93d01e85b75b42181a54192a949c82b549db3d94
font_02_sfnt_off0001434f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1434F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1