Malicious PDF — malware analysis report

Static analysis result for SHA-256 53a7baa2f2cee16b…

MALICIOUS

PDF

81.6 KB Created: 2021-09-11 15:31:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: dd9f30c6e94f580c01444f2629433daa SHA-1: 96d965bb9f7227c641acd211ca95f81754f03e8e SHA-256: 53a7baa2f2cee16b6b8f1d84fb3c6e95c664b21f6fd3ab9f1ecefcd533f3322a
156 Risk Score

Malware Insights

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

The file is identified as a malicious PDF by ML classifiers and ClamAV. It contains numerous embedded URLs pointing to external websites, many of which are hosted on compromised or disposable domains, suggesting a link farm or phishing lure. The presence of these external links and the overall structure indicate an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://smidgel.ru/uplcv?utm_term=how+to+convert+video+to+voice+memo PDF link annotation
    • http://tecsun-moscow.ru/docs/file/95747543122.pdfIn PDF document text
    • https://badrivishal.com/media/43739571953.pdfIn PDF document text
    • http://bibrka-school.org.ua/ckfinder/userfiles/files/bijup.pdfIn PDF document text
    • http://apartament-krokus.pl/userfiles/file/javewidovedogexadodabide.pdfIn PDF document text
    • https://suacuacuontoanphat.com/upload/files/22564920987.pdfIn PDF document text
    • http://sarkar.ie/userfiles/file/30060412234.pdfIn PDF document text
    • http://xn--80aafbanafwvcftiqfecrg2a.xn--p1ai/pict/file/99458703415.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/16134feef787a1---tujeragawosixedu.pdfIn PDF document text
    • http://www.alexgis.com/siteuploads/editorimg/file/39196568335.pdfIn PDF document text
    • https://al-wesam.com/userfiles/files/bedatokageximu.pdfIn PDF document text
    • http://allprintusa.com/admin/images/file/nowerelo.pdfIn PDF document text
    • http://aktifbant.com/resimler/files/58944893840.pdfIn PDF document text
    • http://tranhdaquydep.vn/upload/files/mobaz.pdfIn PDF document text
    • http://pebyte.com/wp-content/plugins/super-forms/uploads/php/files/a9cahokt8ueoj1om8916v19cmo/tagukujekobawodu.pdfIn PDF document text
    • http://prvugkh.ru/uploads/files/24799553594.pdfIn PDF document text
    • http://streetnn.ru/data/upload/ck/files/sijaxefesasibu.pdfIn PDF document text
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/161332e5ed4f5a---96116915016.pdfIn PDF document text
    • https://bruceautoservice.com/files/file/32933662474.pdfIn PDF document text
    • https://nabijdefossa.nl/upload/files/zevezususinepi.pdfIn PDF document text
    • http://computergramm.com/userfiles/file/33110907918.pdfIn PDF document text
    • http://giga.sk/storage/file/fifeto.pdfIn PDF document text
    • http://samtekelektrik.com/files/12351434936.pdfIn PDF document text
    • http://www.thunderesp.com/ckfinder/ckfinder.htmlfiles/noxokurabudifujew.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_off0000daba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDABA 10300 bytes
SHA-256: 825a9a67b21aa05bd8bdf9aeb0be059bb8082840304208cd6e3aa58d38bbca3a
font_01_sfnt_off0000f1df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1DF 18060 bytes
SHA-256: 270bc46f29a9472e50cf00b19b031c2a8805a17f108bd431e8440f2cd0e96546
font_02_sfnt_off00012053.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12053 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1