Malicious PDF — malware analysis report

Static analysis result for SHA-256 681fe14beec3e3ee…

MALICIOUS

PDF

71.3 KB Created: 2021-10-06 15:16:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: d75bed9be8e29272d70dca3a89a5b090 SHA-1: f1cb19ce0531f09f2a8aa507367f945c3c8cdd3c SHA-256: 681fe14beec3e3eee903283e1c3f9d9cf921fd24121dbf041686c39742d9ba3d
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised or disposable domains, indicative of a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. No scripts were extracted, but the structure and URL patterns are consistent with a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://spokoino.ru/i/upload/files/88256547933.pdf In PDF document text
    • http://perfect-gallery.com/userfiles/file/81018132748.pdfIn PDF document text
    • http://yugang360.com/upload_fck/file/2021-10-5/20211005080521970786.pdfIn PDF document text
    • https://ww150001.linebot.net/upfile/files/20211005084838.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16153a3fc43bd4---segozoxipepez.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/1615ce5435565d---mivoziwe.pdfIn PDF document text
    • https://aymexco.ro/ckfinder/userfiles/files/nosegatozuji.pdfIn PDF document text
    • http://hebammenglueck.de/ckfinder/userfiles/files/jolagekawekax.pdfIn PDF document text
    • https://twr1115.net/files/fckeditor/file/zurakiropivixafuz.pdfIn PDF document text
    • https://hoavily.com/uploads/files/17460289886.pdfIn PDF document text
    • http://abwingsjanaf.com/uploads/files/makukoziji.pdfIn PDF document text
    • http://tulga.ru/editor/files/95687182636.pdfIn PDF document text
    • http://wooshin.kr/uploaded/file/856691718614666ea87070.pdfIn PDF document text
    • http://mp-hd.de/data/aktualnosci_imgs/file/loniligixusilevuxe.pdfIn PDF document text
    • https://sidexsideaudio.com/wp-content/plugins/formcraft/file-upload/server/content/files/161455822a4203---4957595817.pdfIn PDF document text
    • http://handgun.ee/media/file/rered.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16155a7a9ddf59---53748563844.pdfIn PDF document text
    • https://readxyz.com/wp-content/plugins/super-forms/uploads/php/files/8215b53c13245c1510c9525d43e6ea36/9202488548.pdfIn PDF document text
    • https://foursservices.com/nbloom/fckuploads/file/6350246858.pdfIn PDF document text
    • http://theydeserveastamp.org/wp-content/plugins/formcraft/file-upload/server/content/files/16144d51f01942---bumivaroruwugavixor.pdfIn PDF document text
    • https://sistemkabin.com/ckfinder/userfiles/files/86249929940.pdfIn PDF document text
    • https://birsamundapark.in/userfiles/files/68247993208.pdfIn PDF document text
    • http://blackivy.pl/userfiles/file/88989167688.pdfIn PDF document text
    • https://zohopinler.com/calisma2/files/uploads/jowos.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=gram+positive+rods+with+sporesPDF 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_off0000b537.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB537 16284 bytes
SHA-256: c5796a5b3c2e1edeee2534c7dab0424da7e127cfb7827fc6ec2174e29f859a0b
font_01_sfnt_off0000deda.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEDA 10700 bytes
SHA-256: bfbe8d8714125180a34117fb50139f56319c06a6013ecbb4eadb088a1349e52a
font_02_sfnt_off0000f78c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF78C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1