Malicious PDF — malware analysis report

Static analysis result for SHA-256 113d435fbc6b4341…

MALICIOUS

PDF

86.6 KB Created: 2021-10-08 08:02:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 49ecb2d59782a649d6fdf0acaf6f1bb7 SHA-1: 7383d5ac8f0b17de2f81b48010c33476e37c7c7a SHA-256: 113d435fbc6b4341a45322ba20bc0c67eaefb91a872a81ee2f76890450d3beed
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to external websites. Several heuristics indicate that these links are part of a link farm, with some hosted on compromised CMS upload storage. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to direct users to phishing or malware distribution sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 http://yevres.fr/ckfinder/userfiles/files/nesegufuzonabavekila.pdf
    • http://physocare.com/Images_upload/files/84606858610.pdf
    • http://optykglowacki.pl/obrazki/files/boxekumivegeforevu.pdf
    • http://tznjl.com/userfiles/files/podatanufusojaxovaru.pdf
    • https://jfava.gemwareserp.com/userfiles/file/vusunikav.pdf
    • http://pk-rowery.pl/user_pict/file/87821292781.pdf
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/30c51413bafeaee9d2935642791eef81/42861648103.pdf
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142215d2face---sowug.pdf
    • http://metall-press.ru/files/rodipetofefoludixitegimix.pdf
    • http://top-rubber.com/admin/fckeditor/editor/filemanager/connectors/upload/file/9939269340.pdf
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614fbdc39cddd---35730645214.pdf
    • https://www.partyshuttlebus.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1615f87ef75a4e---fuxum.pdf
    • https://frennphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614d7594c2cc8---fodizegajesobigel.pdf
    • http://abapaposentados.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161560509ecfea---doneputexivozab.pdf
    • http://kargiskola.ge/myadmin/ckeditor/ckfinder/userfiles/files/55104842174.pdf
    • http://tce.vn/imagesflashupload/file/95301527594.pdf
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/16142f7b846f2e---gabuwikomaluzegomude.pdf
    • https://buonoantonio.it/userfiles/file/799525684.pdf
    • http://noithatachau.vn/webroot/img/files/51662655463.pdf
    • http://toonesk.com/upload/64023820766.pdf
    • http://shinex-auto.com/userfiles/file/jogoberelemaki.pdf
    • https://quanticabtl.com/cms_2018_quantica/sgi_userfiles/userfiles/files/95822513698.pdf
    • https://duext.com/wp-content/plugins/super-forms/uploads/php/files/aac6fd9c960409938f7ec00e56b0c413/gaxuvuzelupedoloxu.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=ghost+town+tentacles
    • 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_off0000e48e.bin
7f2d869f0e5aa6ab71b0169fbfc86aac1d1eb9fc180fbbaefed4350b177ad80a
pdf-font-stream PDF embedded font (sfnt) at offset 0xE48E 10260 bytes
font_01_sfnt_off0000fbb5.bin
0ddb2d6ab231a39de4d2a341eb7f0de7ff18375d3e2918160a85bd8ca9e9fbe2
pdf-font-stream PDF embedded font (sfnt) at offset 0xFBB5 22008 bytes
font_02_sfnt_off0001346e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1346E 16792 bytes