Malicious PDF — malware analysis report

Static analysis result for SHA-256 91a34ac5672801a9…

MALICIOUS

PDF

80.7 KB Created: 2021-07-25 11:49:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 3e8efa0b48b05d0bc22777db56425b0e SHA-1: 1f7ffafa7abd793f6df02141b30ec431b30add06 SHA-256: 91a34ac5672801a9160793e76c52e17a2ed59152fc076e0b8cc9737bfe133175
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to other PDF files hosted on compromised websites, indicating a link farm or redirection scheme. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution. The presence of external URIs and link farm characteristics points towards an attempt to lure users to malicious content or manipulate search engine results.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9780

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://elicopter-de-inchiriat.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a4a85b4ece4---xijadituvitip.pdf In PDF document text
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1606f42edbff8a---40531945305.pdfIn PDF document text
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d1c1d930fe7---29789030338.pdfIn PDF document text
    • https://pezenasenchantee.fr/userfiles/file/51368448516.pdfIn PDF document text
    • https://sakkestadbil.no/userfiles/file/sixefegojowodutivaxu.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160702959bfd1b---58511573180.pdfIn PDF document text
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160a31df0f2985---11208805620.pdfIn PDF document text
    • http://centronegozi.com/public/zosenitaxus.pdfIn PDF document text
    • http://steelbo.com/uploads/admins/u0/files/20210611165734.pdfIn PDF document text
    • https://unosms.us/userfiles/file/mulowujalixamaz.pdfIn PDF document text
    • https://mcq-exambd.com/app/webroot/ckfinder/userfiles/files/1822049696.pdfIn PDF document text
    • http://zonwering-belgie.eu/ckfinder/userfiles/files/kezazividojib.pdfIn PDF document text
    • http://evohome.pl/userfiles/file/minasedege.pdfIn PDF document text
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/1608027ce6196d---gadubuzira.pdfIn PDF document text
    • http://keigan-productions.com/clients/863431/File/95344645331.pdfIn PDF document text
    • http://alompar.hu/uploads/content_files/files/71068062631.pdfIn PDF document text
    • http://bfr-bialapodlaska.pl/userfiles/file/27241701294.pdfIn PDF document text
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609dfdcde4927---9706033355.pdfIn PDF document text
    • https://clinic4lab.com/upload/ckfinder_temp/files/20210701224357.pdfIn PDF document text
    • http://witnesstherealist.com/wp-content/plugins/super-forms/uploads/php/files/8da7b765831782945f4e04d89d409aec/mepipusalowadimenetaxidik.pdfIn PDF document text
    • https://segurosjdd.com/wp-content/plugins/super-forms/uploads/php/files/rqshboic5movh66ev6q7oagvi1/litesiwozigovuzedifel.pdfIn PDF document text
    • https://datajournonepal.org/files/wuxewezos.pdfIn PDF document text
    • http://rchs1964.com/clients/5/58/580abc73d3aac4ea3a2bdd7c75327783/File/wijaviwidomavapotuxun.pdfIn PDF document text
    • https://sandalyecenneti.com/wp-content/plugins/super-forms/uploads/php/files/avg0gh0k1kffi2sbpd86ent914/ruwanewido.pdfIn PDF document text
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160abeb25bfb0d---kesed.pdfIn PDF document text
    • http://www.mediacomriccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607ee2dd83bf5---sepivex.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=sorelle+berkley+4-in-1+convertible+crib+conversion+kitPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c48c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC48C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dc9d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC9D 16092 bytes
SHA-256: 9d5144547e0b729630886a3ad3ce48e7da84b0115899dd9c2390406af6f0fecd
font_02_sfnt_off0000f1e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1E3 10712 bytes
SHA-256: 0ea21ac6b0454bab7ed97f537626888b9320fc5ff30d5ced674c35f5c634522d
font_03_sfnt_off00010ab2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AB2 16348 bytes
SHA-256: 4346730759ac6150c0465ccbc29ae1c74cc028ff65e8c267441372a6e14e2aff