Malicious PDF — malware analysis report

Static analysis result for SHA-256 3578d8dd6624dd88…

MALICIOUS

PDF

87.0 KB Created: 2021-09-17 16:32:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 38ce486c09f4d7c3ce7cd9f76b11e561 SHA-1: 9433e8d85cd96e9418dc2842806bd6568a02bcff SHA-256: 3578d8dd6624dd88826fb5a5d802438b0fe5524ff1bf52f8686318ca40fc2e4e
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external PDF files hosted on various domains, many of which appear to be compromised or disposable. Heuristics indicate this is a link farm, and ClamAV detected it as a phishing trojan. The ML classifier also strongly flagged it as malicious. The primary goal appears to be directing users to malicious content via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://goldmenu.com/userfiles/file/novivasonibajekeset.pdf In PDF document text
    • https://susta.vn/userfiles/file/21191684467.pdfIn PDF document text
    • https://arrayamed.com/userfiles/file/89870901338.pdfIn PDF document text
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16139c0c23092b---99496981780.pdfIn PDF document text
    • http://aimic.com/userfiles/file/nelikutemugu.pdfIn PDF document text
    • http://0225674989.kad.tw/kads/ckfinder/userfiles/files/polubeju.pdfIn PDF document text
    • http://vincitydata.com/uploads/ckfinder/files/povagefirudojazetavot.pdfIn PDF document text
    • http://eastcoastbiker.de/sites/default/files/file/gopufineritowis.pdfIn PDF document text
    • http://vonschickenfremont.com/uploads/files/19796405846.pdfIn PDF document text
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130bc670a753---vezusolenivadeleradaze.pdfIn PDF document text
    • https://allora-tour.by/var/upload/file/37805014452.pdfIn PDF document text
    • https://un7un9b3rl1pa7-99.com/contents/files/93474158466.pdfIn PDF document text
    • http://imaginove.eu/data/Files/64144750918.pdfIn PDF document text
    • http://smalternatywa.pl/media/upload/files/6e4a1fd25a58b798bab5eab85542bcdf.pdfIn PDF document text
    • https://diversifiedhumansolutions.com/wp-content/plugins/super-forms/uploads/php/files/cca90bfce468fa531992bdff40593feb/57838176579.pdfIn PDF document text
    • https://mtmnetwork.net/uploadEditor/files/60044877576.pdfIn PDF document text
    • http://taociren.com/upload/file/210904003004134502e1fvlj5iwag0.pdfIn PDF document text
    • http://akvatoria.by/UserFiles/files/dexejufojo.pdfIn PDF document text
    • http://zhongjiukeji.com/upload_fck/file/2021-9-11/20210911103222375820.pdfIn PDF document text
    • http://clairerolo.com/userfiles/file/2979559915.pdfIn PDF document text
    • http://e-cluny.cz/UserFiles/file/54787145110.pdfIn PDF document text
    • http://teewer.mn/ckfinder/userfiles/files/zujinirukut.pdfIn PDF document text
    • http://webcertain.asia/contentupload/fckeditorUploads/organization_/file/83433200579.pdfIn PDF document text
    • http://dreiseengrundschule.de/files/69636504920.pdfIn PDF document text
    • http://balaton.varosom.hu/userfiles/files/563380303.pdfIn PDF document text
    • http://aucoindeshalles.com/menu/file/86882915370.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=ghost+tube+sls+apk+downloadPDF 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_off0000ee48.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE48 10752 bytes
SHA-256: e817ec5808537363cac1126ee86cb9407116a7e7b2b85a146b40dadcbe793ef0
font_01_sfnt_off000106e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106E1 17996 bytes
SHA-256: e0148f534097af19450f6734424a736142edd44dbaf06e1093bf1b1dabc96a1b
font_02_sfnt_off000135ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x135AD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1