Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7127c893291f4af…

MALICIOUS

PDF

83.5 KB Created: 2021-09-04 05:01:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-02
MD5: b72b8bd1b4d94ec37ac20b3b18f03ab0 SHA-1: 7e26734caaa6ead042b9aba3c42912f340227e88 SHA-256: a7127c893291f4af4b59385133aa81f6dd56024b8d3caa3378b95305d1a36c04
96 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

Heuristics 5

  • 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://boilerservis.ru/uploads/files/topakupi.pdf In PDF document text
    • http://perfectthesale.com/wp-content/plugins/formcraft/file-upload/server/content/files/160735fa0e1de6---kazigudibip.pdfIn PDF document text
    • http://vladjurnalist.ru/archive/file/91115667143.pdfIn PDF document text
    • https://dezsredstvompx.ru/wp-content/plugins/super-forms/uploads/php/files/3aa9af8c8193b48e77c777e0005a9645/5599225646.pdfIn PDF document text
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/160ffd58b48f85---gilaju.pdfIn PDF document text
    • https://churchosonline.com/wp-content/plugins/super-forms/uploads/php/files/748c4cb74c3035f0f35440a389fcbb82/32862528190.pdfIn PDF document text
    • http://cerrutistudio.eu/userfiles/files/44515768760.pdfIn PDF document text
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611d1fc0b008d---45319044105.pdfIn PDF document text
    • http://skomi.ru/img/files/file/purigadifisibenom.pdfIn PDF document text
    • http://asesorialuishervas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ceec5b6312---detorabu.pdfIn PDF document text
    • https://alkalacarservice.com/public_html/userfiles/file/88956630213.pdfIn PDF document text
    • http://starinviter.com/ckimagefiles/15463790071.pdfIn PDF document text
    • https://bandotrading.it/uploads/file/78719837786.pdfIn PDF document text
    • https://laflammerouge.ch/userfiles/files/valilazupedapewir.pdfIn PDF document text
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/160b33621837a9---34961013074.pdfIn PDF document text
    • http://www.majorisinvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca499e0d72---44978258021.pdfIn PDF document text
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b7417a69f7f---jesogamularo.pdfIn PDF document text
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d098aa7ee3---togakolononiwefefabul.pdfIn PDF document text
    • https://resortweeks.pro/userfiles/file/mufebixezunid.pdfIn PDF document text
    • http://huntland.hu/upload/file/81176573615.pdfIn PDF document text
    • http://www.restorationservice.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160e8305ff1208---46537081873.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=unions+and+intersections+worksheetPDF link annotation
    • 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_off0000de42.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE42 10608 bytes
SHA-256: 1e6fb7645aa33a53537becbb34433c2ceab188f1fe9592fe444362637644fc6b
font_01_sfnt_off0000f681.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF681 19240 bytes
SHA-256: 9894ed97f7556de76e8b959ef3e12f1a27902febb2fd529e47448d29d57ba15e
font_02_sfnt_off0001289f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1289F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1