Malicious PDF — malware analysis report

Static analysis result for SHA-256 d71ac36953ad6d6d…

MALICIOUS

PDF

113.9 KB Created: 2021-07-01 10:50:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 6c06cbc9fafefe15501cd96e03e87308 SHA-1: 67d955d56732baf94337c850c96cd107e493b6d5 SHA-256: d71ac36953ad6d6d6f7078664d0bdbb433709be153e925f9a0df055223d1deae
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The 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 URLs pointing to compromised WordPress sites or disposable domains, suggesting it's used to distribute phishing content or malware. The PDF structure itself does not contain executable scripts, but the embedded URLs are the primary attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9886

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://oniceh.ru/uplcv?utm_term=8+cell+embryo PDF link annotation
    • http://deauville.ru/files/file/75433287666.pdfIn PDF document text
    • http://xn--e1aazeoc7d.xn--p1ai/images/shared/file/9627354959.pdfIn PDF document text
    • http://chia4kids.ru/ckfinder/userfiles/files/76592004458.pdfIn PDF document text
    • http://terminsk.by/pics/files/gadepovizusawim.pdfIn PDF document text
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/16076bcc69425b---29741414467.pdfIn PDF document text
    • https://fermuar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac53c04d909---87908359456.pdfIn PDF document text
    • http://albertopizzetti.it/userfiles/files/8562302631.pdfIn PDF document text
    • https://www.ptlittleflower.org/wp-content/plugins/super-forms/uploads/php/files/ik456gdeeu4j06utrdi3c0krh6/46823140502.pdfIn PDF document text
    • http://tablica-nieruchomosci.pl/uploades/fckeditorfile/penaxuzav.pdfIn PDF document text
    • https://www.clubmanizales.com.co/wp-content/plugins/formcraft/file-upload/server/content/files/160708c70a4a4b---40723865072.pdfIn PDF document text
    • https://www.hinogas.com/wp-content/plugins/super-forms/uploads/php/files/5c9ktdvs5d0v50uvu7pacnbch9/xaruxekesolawodebigomi.pdfIn PDF document text
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160d923d88ee02---wusapenuvegili.pdfIn PDF document text
    • http://fittbikese.hu/files/file/45598015340.pdfIn PDF document text
    • http://savaksangida.com/resimler/files/7390343007.pdfIn PDF document text
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/7d349c8b54efef165bcdc341747bd54b/befojarapones.pdfIn PDF document text
    • http://caratow.eu/userfiles/file/8376431341.pdfIn PDF document text
    • http://mgmkt.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160be83b028bdc---20899274786.pdfIn PDF document text
    • https://socialchangefactory.org/wp-content/plugins/super-forms/uploads/php/files/2c143b3ae49e8e4ea5e0c9abce32ca36/fiwasuwitazijitejeraxem.pdfIn PDF document text
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/2d57ea705c006d2b2454beaccbd3f9d0/dopozobova.pdfIn PDF document text
    • https://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/24586aba00b0d2e24cc604d59d6ad642/71335293005.pdfIn PDF document text
    • http://imhkayseri.com/resimler/files/85606866059.pdfIn PDF document text
    • http://abapaposentados.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c73ec60a054---38163214443.pdfIn PDF document text
    • https://allianztc.ro/files/file/60489539296.pdfIn PDF document text
    • http://groupkaishan.com/d/files/69471606654.pdfIn PDF document text
    • https://wilsonbarrera.com/inicio/wp-content/plugins/formcraft/file-upload/server/content/files/1608508d1809fb---titanekamedopenoxif.pdfIn PDF document text
    • http://asdgolfclubtoscana.com/writable/public/userfiles/file/kukoze.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_off00015d0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15D0B 17316 bytes
SHA-256: d4c30ae906512e27a8e07fe40796d640b4046ce84420f6965106793f82b112fa
font_01_sfnt_off00018a90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18A90 10132 bytes
SHA-256: 8852fcdd5f2801e2293d96dfd3830a732542726b383ba47938fbc5106754f78f
font_02_sfnt_off0001a13b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A13B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1