Malicious PDF — malware analysis report

Static analysis result for SHA-256 c976b31e48b06ef5…

MALICIOUS

PDF

80.1 KB Created: 2021-09-18 21:59:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: c79cf110293364c30eaefa63ab5dcea0 SHA-1: af18914be31d0be15a1f905e0b6b7c6072d6f4da SHA-256: c976b31e48b06ef5bca9c261d17fa8b941f5125b40345bfba440aa2a65b24e69
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating it's a phishing or trojan delivery mechanism. It functions as a link farm, with numerous embedded URLs pointing to compromised CMS uploads and disposable hosting, likely to redirect users to malicious sites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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
  • 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.
  • 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://huntic.ru/uplcv?utm_term=dexter+tv+on+firestick PDF link annotation
    • http://tbff-bygg.se/img/files/17434162486.pdfIn PDF document text
    • http://ktai.lmg.jp/upload/file/sovog.pdfIn PDF document text
    • http://checopharma.com/upload/files/bowixowopewamividumu.pdfIn PDF document text
    • https://zippy-inc.com/app/webroot/userfiles/files/lezefurojamijigomit.pdfIn PDF document text
    • http://bbfederico2.net/userfiles/file/88861455621.pdfIn PDF document text
    • https://lecourbe.dk/userfiles/file/20422587734.pdfIn PDF document text
    • http://superfasttv.com/uploads/files/33704712927.pdfIn PDF document text
    • https://lotteppta.com/beta/assets/file/82644041331.pdfIn PDF document text
    • http://cinebuzz.be/uploads/userfiles/files/sazisub.pdfIn PDF document text
    • http://umrllc.com/userfiles/files/53410197103.pdfIn PDF document text
    • https://stpetejazz.com/wp-content/plugins/super-forms/uploads/php/files/apmsi8b8n1t0lrjgmm1855pnfr/54620947445.pdfIn PDF document text
    • http://star-transform-moscow.ru/uimg/files/27692779159.pdfIn PDF document text
    • http://ilksolar.com/Images/Media/files/80309530476.pdfIn PDF document text
    • https://somogyplusz.hu/files/nekilejug.pdfIn PDF document text
    • http://netinflux.net/userfiles/file/buresiwaguveb.pdfIn PDF document text
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/85798fb893582ff02a244d655f1dcec8/99187374327.pdfIn PDF document text
    • https://ags-car.60km.com/upload/files/lulaboduxutalobutipejubim.pdfIn PDF document text
    • http://infiniti.e-library.tw/uploads/files/2458078994.pdfIn PDF document text
    • http://deborahkay.com/ckfinder/userfiles/files/dumime.pdfIn PDF document text
    • http://udokutscher.de/gfx/userfiles/files/17490056208.pdfIn PDF document text
    • http://evpltravel.com/xv_image/file/nijipezixigamanunidijis.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/16142911798548---doxupuwudefiwenene.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_off0000d52e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD52E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ed40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED40 17848 bytes
SHA-256: 4dd117584bef4a11cef507c410b625ad315c53ab739cfb04a7ef1b4195b06cf5
font_02_sfnt_off00011b12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B12 10380 bytes
SHA-256: d9310321f2367295ac5ba7d3e30e657c01322b11e960c3afae08e6458c25738e