Malicious PDF — malware analysis report

Static analysis result for SHA-256 a92c6ba1ab91adc7…

MALICIOUS

PDF

74.5 KB Created: 2021-09-10 08:02:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 4f3698032939e571f3ecc24c74d2ebc2 SHA-1: de3812633fc0e92cccf2fe0c30b089da8870590d SHA-256: a92c6ba1ab91adc7705f85b2a5c70ca775da5c656902a51530d93eba8a001734
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised websites or are part of a link farm designed to manipulate search engine rankings. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lead users to phishing or malware-hosting sites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user interaction but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 http://st-ark.it/userfiles/files/26493228657.pdf In PDF document text
    • https://intekcanada.com/ckfinder/userfiles/files/41808308023.pdfIn PDF document text
    • http://uran-berlin.com/userfiles/file/16340792487.pdfIn PDF document text
    • http://avandcie-energy.com/ckfinder/userfiles/files/ruwofuvinuwasovak.pdfIn PDF document text
    • http://harringtonassociateslaw.com/Test/JabzMedicalBillingService/userfiles/file/kojajopuxiwowuvapisetabak.pdfIn PDF document text
    • https://chuyennhakienvangvn.net/upload/files/fejopur.pdfIn PDF document text
    • http://silarperu.com/UserFiles/file/24915969640.pdfIn PDF document text
    • http://architettoseneca.com/userfiles/files/13012953641.pdfIn PDF document text
    • https://www.horisunmauritius.com/wp-content/plugins/super-forms/uploads/php/files/320495e3232334c84da0d9aa5bf86f65/77812790447.pdfIn PDF document text
    • http://chanakyaaerospacedefence.com/userfiles/file/rebopetafuzovuduvize.pdfIn PDF document text
    • https://littleedupark.com/ckfinder/userfiles/files/83653532048.pdfIn PDF document text
    • http://spadhotel.com/basefile/spadhotelcom/files/9106066219.pdfIn PDF document text
    • http://luxcottage.ru/stroykamen/userfiles/file/44870570991.pdfIn PDF document text
    • https://ermolino.mebel18.com/uploads/files/zevipuzewesifa.pdfIn PDF document text
    • http://cabinet-blin.fr/ressource/site-image/files/22658956287.pdfIn PDF document text
    • http://khmim.com/ckfinder/userfiles/files/tumigezagixakeka.pdfIn PDF document text
    • https://www.agencesramos.com/ckfinder/userfiles/files/434044884.pdfIn PDF document text
    • https://relleno-acidohialuronico.com/wp-content/plugins/super-forms/uploads/php/files/259be89211219edbf6606bd8760dbaeb/82513223470.pdfIn PDF document text
    • https://californiaoptionsrealestate.com/wp-content/plugins/super-forms/uploads/php/files/f8345e8df993bd11f91a1e26e486a3dc/velogekoduraro.pdfIn PDF document text
    • http://gelikonline.ru/content/Files/sukulubuxamumirofivi.pdfIn PDF document text
    • http://mn-print.ru/ckfinder/userfiles/files/zijobelepezejixowifu.pdfIn PDF document text
    • http://domki-kopalino.pl/pliki/72595220912.pdfIn PDF document text
    • http://am-assets.com/aom/magnolia/userfiles/file/71523886284.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=vlc+players+for+androidPDF link annotation
    • 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_off0000c0b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC0B9 16716 bytes
SHA-256: 0430672c805121fc0555479a91127c008a4dae253976d1681949decc5ce0e6f2
font_01_sfnt_off0000ec11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC11 10600 bytes
SHA-256: 618ddeee029a214a4dc270977f33372dba15d29e3e3ea2fadbb2590f8d88eadb
font_02_sfnt_off00010467.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10467 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1