Malicious PDF — malware analysis report

Static analysis result for SHA-256 437b8e7350cb0025…

MALICIOUS

PDF

70.2 KB Created: 2021-09-25 20:00:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f8f11cd7948217b966371fba260a36eb SHA-1: 98155452d9234d25a7eb38e75571145f1dd4cede SHA-256: 437b8e7350cb0025d642749e7ecb4285dae82d8719af072bdd994612b853e23e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a phishing or trojan threat. It contains numerous URLs, many hosted on compromised WordPress sites or disposable domains, suggesting a link farm designed to redirect users to malicious content. The presence of embedded URLs and the nature of the heuristics point towards an attempt to lure users to external sites for further compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

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://nomylo.ru/uplcv?utm_term=if+conditional+exercises+with+answers+pdf
    • http://hidropro.hu/upload/40295858593.pdf
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/161494ca20ebcd---fuvoso.pdf
    • http://wintec-samu.hu/uploads/files/45079188172.pdf
    • http://proximeo.com/ckfinder/userfiles/files/jipufukixujuzikesi.pdf
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/161480001a315b---pawev.pdf
    • https://costumeworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140c4a36cac3---zejepaw.pdf
    • http://24x7taazasamachar.com/assets/ckfinder/core/connector/php/uploads/files/96080138531.pdf
    • https://get-insurance.in/ckfinder/userfiles/files/7591787889.pdf
    • https://indianhairtransplant.com/ckfinder/userfiles/files/63858058066.pdf
    • https://www.pactforfamilies.org/ckfinder/userfiles/files/56322287388.pdf
    • http://alexandersorokolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/xomagozudowava.pdf
    • http://pension-erlkoenig.de/img/editor/file/tadarorovofe.pdf
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161382895214ff---24430754017.pdf
    • http://laboratoriologos.it/userfiles/files/61420970202.pdf
    • https://deltagroup.bg/uploads/file/begevagudepabajefiroven.pdf
    • http://embody.box8websites.com/ckfinder/userfiles/files/luwepipapopu.pdf
    • https://tybistanbul.org/resimler/files/35101705869.pdf
    • http://rigassprotes.lv/uploadz/file/83717789079.pdf
    • http://geostudio.eu/userfiles/files/97937382781.pdf
    • https://siphouse96.com/wp-content/plugins/super-forms/uploads/php/files/fd2b9c4f175fbb3a13dbb65e7fa5295a/22419739410.pdf
    • http://kco.su/userfiles/file/nokapujob.pdf
    • https://irisapp.cn/uploadfiles/fckeditor/20210914/file/16315743466261.pdf
    • http://geodavidepini.it/userfiles/files/bunuzawebug.pdf
    • https://it-remarketing.pl/app/webroot/media/files/18540859401.pdf
    • http://problemconsulting.com/img/download/files/32640982880.pdf
    • https://bjjewels.net/nbloom/fckuploads/file/28860036428.pdf
    • 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_off0000b2f1.bin
370a4a80a87a55ffa13d23a49a367ef481170f19b928f7e9e410f2ae7e6b78df
pdf-font-stream PDF embedded font (sfnt) at offset 0xB2F1 15556 bytes
font_01_sfnt_off0000d9c8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD9C8 16792 bytes
font_02_sfnt_off0000f1df.bin
9491dff0249131d88de9651c882318b3148fafb9468148804ca0aa5c3cfa7950
pdf-font-stream PDF embedded font (sfnt) at offset 0xF1DF 10856 bytes