Malicious PDF — malware analysis report

Static analysis result for SHA-256 d1819087c421ed20…

MALICIOUS

PDF

70.4 KB Created: 2021-09-11 06:37:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 3b51af2645260c8226f9ffcffc4e4a48 SHA-1: 77f7f73409996688fec36719a3716054277ed840 SHA-256: d1819087c421ed20d8a581b66e9a9a75ee789bd791db884b2bea9b9b94ecadd0
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URLs, with one specifically identified as a link farm on disposable hosting, suggesting a phishing or malware distribution scheme. The PDF structure and embedded URLs point towards a spearphishing attachment attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://medvor.ru/uplcv?utm_term=degree+measure+of+an+arc+calculator PDF link annotation
    • http://theloanwala.com/userfiles/file/dilixoxedunewiwuged.pdfIn PDF document text
    • http://dragonspond.com/uploads/files/72027563509.pdfIn PDF document text
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/161322dd3a451f---67701287215.pdfIn PDF document text
    • https://cncostruzioni.com/userfiles/file/pagunadimipexesabavoboli.pdfIn PDF document text
    • http://polaryachtmanufactory.com/res/wysiwyg/file/27230632703.pdfIn PDF document text
    • http://posicert.com/upload_fck/file/2021-9-4/20210904170833919586.pdfIn PDF document text
    • http://rgn2u.com/userfiles/files/8230668109.pdfIn PDF document text
    • http://autothudo.vn/upload/fck/file/zesumo.pdfIn PDF document text
    • http://dieukhactransam.com/uploads/files/jarajerederux.pdfIn PDF document text
    • http://kiuruvedenlukio.fi/tiedostot/file/lizovanosaja.pdfIn PDF document text
    • http://kartywspomnien.pl/uploads/assets/file/tokadopofotoni.pdfIn PDF document text
    • http://thucancakoihikari.com/luutru/files/garavesozufalusobagixakam.pdfIn PDF document text
    • http://murito.fr/ckfinder/userfiles/files/86354268621.pdfIn PDF document text
    • http://yearbookplus.com/uploads/ckfinder/files/32603910872.pdfIn PDF document text
    • http://geasit.it/userfiles/files/nupogekotewedojetanozir.pdfIn PDF document text
    • http://xn--2osv9pt2jfpt.com/uploadfiles/files/44435767564.pdfIn PDF document text
    • https://onutglen.com/caningest/images/file/gapojowesufuzutejuv.pdfIn PDF document text
    • http://shanghaicruiseparty.com/uploads/file/vesarerumuxa.pdfIn PDF document text
    • http://abwrosedale.com/uploads/files/47728260100.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/532b54724af33556ec66c606fac265f6/71949175476.pdfIn PDF document text
    • http://medtravel.pro/images/hand_uploaded/files/33632937998.pdfIn PDF document text
    • https://nstyapi.com/resimler/files/6812760013.pdfIn PDF document text
    • http://xn--80aa5alfu.kz/file/rojixapuzupajam.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_off0000b385.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB385 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cb97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB97 15728 bytes
SHA-256: 24c170025a3009e71e2c41e019ed4b26f5cb21d36d806c643ec1d7a85a4e14bf
font_02_sfnt_off0000f323.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF323 10688 bytes
SHA-256: 0608ac06b19ef755d6fcc2b2802173ce622860400f4f55b12d9854c90fbf2b7a