Malicious PDF — malware analysis report

Static analysis result for SHA-256 83f767ac7821208c…

MALICIOUS

PDF

92.9 KB Created: 2021-06-26 01:02:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: fe1fe7179a83debec42f669e7e163b3b SHA-1: af76f98fd3c6078211e4b064ec1d4ff0080ebdf4 SHA-256: 83f767ac7821208c217831beab70dd1699bc468930d64383db919942baee068a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites, likely serving as a distribution point for phishing or malware. The presence of external URIs and link farms on disposable hosting further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9937

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 https://medvor.ru/uplcv?utm_term=tier+2+intervention+strategies+for+math
    • https://advancedbusiness.co/wp-content/plugins/super-forms/uploads/php/files/819e1faf96245038233d1f7d7b8b660b/zuvavorokefewarazirileta.pdf
    • http://medica-brno.com/files/13398503904.pdf
    • https://pelletier-tp.fr/ckfinder/userfiles/files/fomorezipijifebisivod.pdf
    • http://www.cargeacrew.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606d582c7fcf9---misamumexulaxufopodobesab.pdf
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/107694ae0b15ec38706874aa8160aef1/13143454123.pdf
    • https://www.ideaklinikbakirkoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c0cbde83ab5---nodoxanadenavumimutefema.pdf
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/1607093330b7fb---ripogalejowik.pdf
    • http://www.urbanwaterways.info/files/27616120130.pdf
    • https://www.onestopnaturalstore.ca/wp-content/plugins/super-forms/uploads/php/files/m5nnc2nes1p97r0hqm8opvg642/25115661495.pdf
    • https://themodernla.com/wp-content/plugins/super-forms/uploads/php/files/e3d71fe7f1d71c53f1e08bf6249ea2d5/redekanal.pdf
    • http://lavera.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a1ee09e7e47---67462066045.pdf
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b84a351ef2d---91890091104.pdf
    • http://dungcubepgiangtrinh.com/webroot/img/files/salulu.pdf
    • https://abofahed.com/userfiles/file/19586213666.pdf
    • http://cuatro-pr.org/sites/default/files/file/1600713015.pdf
    • http://stinpo.com/ckfinder/userfiles/files/ridosogupu.pdf
    • http://aliceinformaticasrl.com/user/pages/85382689915.pdf
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/b55b0f6a82b97bb023b5d5abdcca718d/rowivakazuxesujuxo.pdf
    • http://aleeblog.com/wp-content/plugins/super-forms/uploads/php/files/n0gpcsg7f0jdsjf5sc02qbii36/77379540080.pdf
    • https://davebakeragency.com/wp-content/plugins/super-forms/uploads/php/files/17fa50e0653b9130be3b3e963b7da2d8/35563727689.pdf
    • http://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/0asha1o7b6n87kelsaf0n0b1i8/6892256700.pdf
    • http://otoozevran.com/resimler/files/fatexaje.pdf
    • https://www.sevgiliyevideo.net/wp-content/plugins/formcraft/file-upload/server/content/files/160bba57fd00ab---fidoge.pdf
    • https://choiceenergynetwork.com/wp-content/plugins/super-forms/uploads/php/files/e6dde93fdd8b3a62327c277ba19c6f25/daxatojul.pdf
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160719117a5232---76811684468.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_off00010917.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10917 16792 bytes
font_01_sfnt_off00012129.bin
ce0eceed8cc9b98df8bd02901a214085ee59824d18ee5d927cf1bc01b773cb08
pdf-font-stream PDF embedded font (sfnt) at offset 0x12129 17076 bytes
font_02_sfnt_off00014d4a.bin
dc283834dd56a04927e99c5a95b63f054eef94c868828ba0526c1170ac72fabf
pdf-font-stream PDF embedded font (sfnt) at offset 0x14D4A 10764 bytes