Malicious PDF — malware analysis report

Static analysis result for SHA-256 7b60266673d4b31a…

MALICIOUS

PDF

75.5 KB Created: 2021-10-12 04:24:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4b4109b7638b69db2279967efd762fd6 SHA-1: d5d2ffa1a7d71ffd94dc9408bc05009114601f16 SHA-256: 7b60266673d4b31a18fc3d5b7c8baba2a34e232d6ac5d43ef28aa02b8273e026
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to other PDF files hosted on various domains. Several heuristics indicate this is a link farm, with some links pointing to compromised WordPress upload storage. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for SEO spam or to distribute further malware. No scripts were extracted, and the document body was unreadable binary data.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://griby.biz/ckfinder/userfiles/files/jexinodijizonub.pdf
    • https://tessuno.com/upload/files/6144010177495.pdf
    • http://studioingegneramato.com/userfiles/files/46428952477.pdf
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/161313556b9c70---53713713797.pdf
    • https://okinawa4d.com/contents/files/70067764389.pdf
    • http://elfobchod.cz/foto/Image/file/rosugut.pdf
    • http://huyminhplastic.com/upload/files/zezixopaxusomawopejedapal.pdf
    • http://morenoroofing.com/wp-content/plugins/formcraft/file-upload/server/content/files/16148f9217b896---44517090341.pdf
    • https://www.havanasalsa-dance-tours.com/wp-content/plugins/super-forms/uploads/php/files/01c68b38edd211e2fa908b6a4ffa28af/nofedo.pdf
    • https://h016s5or78-du3.com/contents/files/xezudabix.pdf
    • https://iphone-odklep.si/vsebina/loguvajenipazisit.pdf
    • http://nofatrans-int.com/userfiles/file/57182474668.pdf
    • http://idrogastermoclima.it/Utentifile/FCKPage/file/51492122931.pdf
    • https://eliteplacementagency.com/uploads/files/18791974450.pdf
    • https://www.adelaarenergy.com/wp-content/plugins/super-forms/uploads/php/files/qpd62agcke1cq5n9hroorlgv0d/zikutabexu.pdf
    • http://china-hold.com/UploadFile/file/20210904205434483.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614a0392df2f4---mipiferomapozujokome.pdf
    • http://startent.ru/SITE/files/editor/file/26133723336.pdf
    • http://jingyilin.org/uploads/file/vumamegagavotanujagulek.pdf
    • https://dfkcnc.shopper-store.net/file/files/13282472755.pdf
    • http://status-go.net/gfx/userfiles/files/70021911198.pdf
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/cc8d516f38ac54e829db466a952c595e/zorozi.pdf
    • https://abcoegypt.com/userfiles/files/27775871004.pdf
    • http://feedproxy.google.com/~r/Xvkpad/~3/xPAns0MRe5M/uplcv?utm_term=nitrogen+of+pyrrole+is+best+carried+out+using
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bbb8.bin
8bd2a91d7f8247eef7fd4285047c8944dcf8df01a20c9e1f97dbd7da4a0ab0dc
pdf-font-stream PDF embedded font (sfnt) at offset 0xBBB8 11128 bytes
font_01_sfnt_off0000d56f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD56F 16792 bytes
font_02_sfnt_off0000ed81.bin
fcc67ee76dd9c73ced29bdd2222c08ec298a1c610485309a31d2650df2784cba
pdf-font-stream PDF embedded font (sfnt) at offset 0xED81 19900 bytes