Malicious PDF — malware analysis report

Static analysis result for SHA-256 af387ffc7c1bc40e…

MALICIOUS

PDF

88.7 KB Created: 2021-07-21 22:26:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 3c17ea4bf2d6a7445f1fd426038a9d30 SHA-1: 579f343f11531532851978a967fb5e641127e295 SHA-256: af387ffc7c1bc40e2213236154bd3f65eaa601b0629009e7be2e402c7602856d
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS uploads and disposable hosting, suggesting a phishing or malware distribution scheme. The document body was unreadable, but the presence of numerous external links strongly supports the link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

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://anhuifan.com/upload_fck/file/2021-7-2/20210702094756577042.pdf In PDF document text
    • http://cesishotel.lv/res/wysiwyg/file/depejonegop.pdfIn PDF document text
    • http://grani-tonkogo-mira.ru/wp-content/plugins/super-forms/uploads/php/files/c63cc4149deec6207a5b5a77732242a0/67921858786.pdfIn PDF document text
    • http://artospace.com/pics/file/rukofamamitonolisegevix.pdfIn PDF document text
    • https://www.synergyheart2heart.team/wp-content/plugins/super-forms/uploads/php/files/qsvtm1kgs2tm4ah48hue456g6m/nixumusuza.pdfIn PDF document text
    • https://www.ideaklinikbakirkoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ba0aadf913---kifizajizubuwenez.pdfIn PDF document text
    • https://www.etbsupplies.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607788e224c9c---xurizimanobato.pdfIn PDF document text
    • https://rtvpuls.com/ckfinder/userfiles/files/texovapumakixipog.pdfIn PDF document text
    • http://www.julitolaschools.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078ddfdaade2---togebebufa.pdfIn PDF document text
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/160736e152fb36---92873129286.pdfIn PDF document text
    • http://testplanet.nl/uploads/files/fawukexedokaratufa.pdfIn PDF document text
    • https://www.blackandwhite-salon.com/wp-content/plugins/super-forms/uploads/php/files/5a497a9e9aa823bde36361549a640394/lemubefurinofafixemenovaw.pdfIn PDF document text
    • https://hotelritariccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/160919f04e099f---9394013534.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/g4cibsslvt62uidks3l5cbr8qq/25004319147.pdfIn PDF document text
    • https://benqmusicworkshop.com/fupload/file/panavuj.pdfIn PDF document text
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/c456279e48bfc6071381167d0ff31a34/63039343045.pdfIn PDF document text
    • http://lecieldesandes.fr/ckfinder/userfiles/files/pofat.pdfIn PDF document text
    • http://limitlessillusion.com/wp-content/plugins/super-forms/uploads/php/files/96613bae4cf4f8ffc11365c71965329e/95189255048.pdfIn PDF document text
    • http://qunjl.com/userfiles/files/zenuwakekivi.pdfIn PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b117fb40de7---83095137399.pdfIn PDF document text
    • http://solarexperten.ch/fckeditor/editor/images/file/dadigejuwewupavosikalawu.pdfIn PDF document text
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2891be3dbb---12569821290.pdfIn PDF document text
    • http://haiphongcontest.com/images/files/ludajibozasokezuzixefemax.pdfIn PDF document text
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/16074a79b66866---leraboxodediborigakozob.pdfIn PDF document text
    • http://www.naturapreserved.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072f68262f23---88826034775.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=up+the+tics+come+onPDF link annotation
    • http://perfecturology.cafe24.com/upload/editor/imagefile/posepewaxibelazanupomuluk.pdfIn PDF document text
    • 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_off0000f865.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF865 10336 bytes
SHA-256: e848d01aaebc35b91cc2e920b5e266dc485643c4f5ae17b03921467f394d458d
font_01_sfnt_off00010f95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F95 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000127a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127A7 16736 bytes
SHA-256: 78ec35625b2ea53a574c40a1755eb615011a48498de700fd6784bd512d22f2b1