Malicious PDF — malware analysis report

Static analysis result for SHA-256 e8ce16a3ad780935…

MALICIOUS

PDF

80.2 KB Created: 2021-08-09 20:31:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 5dc9c6aeb7a0ed41b15ae05adc525946 SHA-1: 8149414c2b546309a9125f338e78c2f1213dcc60 SHA-256: e8ce16a3ad78093501d1503288e0189f01c2fb8d5e218f2d66e1dce388eb8912
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1190 Exploit Public-Facing Application

The PDF file contains a large number of embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm or SEO poisoning tactic. The ML classifier also flagged this PDF as malicious with high confidence. No scripts were extracted, and the document body was unreadable, limiting further analysis of the specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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 https://crysiq.ru/uplcv?utm_term=lab+topic+3+diffusion+and+osmosis+answers PDF link annotation
    • http://nuestratierrapremios.com/campannas/file/34805122529.pdfIn PDF document text
    • http://diacritic.org/travel/app/webroot/img/files/nutitakofaxapomumum.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160ec4dc12a75b---xoxinemedagopisojomutu.pdfIn PDF document text
    • http://balassalaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/wibolabumonexum.pdfIn PDF document text
    • http://klasykarozrywki.pl/public/images/fck/file/87558996023.pdfIn PDF document text
    • http://bezpieczna-strefa.pl/wp-content/plugins/super-forms/uploads/php/files/4163b56a0a53dbd08e6dfb8bdafc1736/majiladepunemu.pdfIn PDF document text
    • https://fo-prefectures.com/pages/files/78996889947.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5bcd1a908b---dajizaben.pdfIn PDF document text
    • https://dazzlin.co.uk/wp-content/plugins/super-forms/uploads/php/files/3f2c284798665eaaf0fbf85912b7fce6/nisowisajunoboxivipabugix.pdfIn PDF document text
    • https://yuktiedu.com/wp-content/plugins/super-forms/uploads/php/files/c42d5b956f7750109fa2c9063a8530e9/49691320763.pdfIn PDF document text
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/a586026b111426475172f8c3162618da/jaminisexodixojamibu.pdfIn PDF document text
    • http://targhevaticane.it/userfiles/files/vototejitivu.pdfIn PDF document text
    • http://www.webtony.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16076e04718ab8---sobakefesidafofogir.pdfIn PDF document text
    • https://tocgia247.com/wp-content/plugins/super-forms/uploads/php/files/1cgbnsqjcl8vvl3akknuj0bgql/xomopixabizubironor.pdfIn PDF document text
    • http://kuehllawpc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/89979622935.pdfIn PDF document text
    • http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/160770fedbca76---dusulazu.pdfIn PDF document text
    • https://sckstone.com/wp-content/plugins/super-forms/uploads/php/files/4f2f00ec94cdba2b44ffc180ad98984c/ribuguvotujat.pdfIn PDF document text
    • http://peggylittlelawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/dujelov.pdfIn PDF document text
    • https://jfefood.com/wp-content/plugins/super-forms/uploads/php/files/c64a9865acfb19c6e43750f82cd2d0e0/97403637416.pdfIn PDF document text
    • https://www.andeanskyline.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7499fb1db3---basetigikadifito.pdfIn PDF document text
    • http://fixafilm.se/userfiles/file/91411554273.pdfIn PDF document text
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1609662c383c22---41573531701.pdfIn PDF document text
    • http://oxigensupplies.com/shipinc/userfiles/files/30977046600.pdfIn PDF document text
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071025f2e55b---82067849991.pdfIn PDF document text
    • http://unseenadventure.com/userfiles/file/83560630568.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_off0000d616.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD616 11192 bytes
SHA-256: e6f323286dfec2f206bf2fe00e18e6d8b62b1a15cd8d8119878529c8c0529dcb
font_01_sfnt_off0000f02f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF02F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010841.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10841 16632 bytes
SHA-256: c545daff62ce710c8110194bc295030ac0090e6b35ceea1084720e65a1945fda