Malicious PDF — malware analysis report

Static analysis result for SHA-256 f38bd3f99aee4c83…

MALICIOUS

PDF

84.0 KB Created: 2021-09-06 21:45:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 33636ac18e2e8a472fb741f6fd5f3a9b SHA-1: bc06d0b59ae09e14bfe7843a7f07ac4499e0434c SHA-256: f38bd3f99aee4c837b231a6614f67f24772490db212575bad0e98fc9815bf539
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users to potentially malicious content. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious link farm attack pattern. No scripts were extracted, limiting the analysis to the URL structure and heuristic findings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://101-games.ru/images/uploads/files/jexinurububisuru.pdf In PDF document text
    • https://moma-restaurant.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1becc444fa---64938730636.pdfIn PDF document text
    • https://dermatologie-francophone.com/userfiles/file/43294869518.pdfIn PDF document text
    • http://writtenmail.com/upload_images/file/waxebek.pdfIn PDF document text
    • http://eventechsite.com/files/files/nogovizapidiwapasetogan.pdfIn PDF document text
    • https://tapetcenter.ro/app/webroot/files/userfiles/files/82539053115.pdfIn PDF document text
    • https://icbacademy.com/upload/files/21810984483.pdfIn PDF document text
    • http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/161315da84d05e---51521609292.pdfIn PDF document text
    • http://napiarsaigh.com/images/mipoxefujopusaliwurifeko.pdfIn PDF document text
    • http://sergey-yushkov.com/pict/file/46660484968.pdfIn PDF document text
    • https://fourseasons.events/wp-content/plugins/super-forms/uploads/php/files/68aff0473f61c42fa15e61c3e9e2f866/25834955502.pdfIn PDF document text
    • https://www.scilights.com/wp-content/plugins/super-forms/uploads/php/files/ac53475c83e1135ddd890f412bbba1cc/68867726355.pdfIn PDF document text
    • http://purepoem.com/resource/docContentImg/file/2021-08-04/b9da873855d61d1f17b068f4251c7ad2.pdfIn PDF document text
    • http://subventionsbetrug.de/wp-content/plugins/super-forms/uploads/php/files/lusg4miuugehafdbj621rlujcf/jitobutixenujixutofefujit.pdfIn PDF document text
    • https://www.electriclighting.com/wp-content/plugins/super-forms/uploads/php/files/ec16178d7ccf3b0d1d11db27977382ce/73418196533.pdfIn PDF document text
    • http://almar-bus.pl/userfiles/file/91770097727.pdfIn PDF document text
    • https://soudurelauziere.com/upload/editor/file/98558888470.pdfIn PDF document text
    • http://portalcom-b2b.es/img/user///file/_0749903001624057699.pdfIn PDF document text
    • https://kueapem.com/contents//files/65482331422.pdfIn PDF document text
    • https://xlspandoek.nl/userfiles/file/74847038111.pdfIn PDF document text
    • https://zakarpattya-tour.com/upload/90063393413.pdfIn PDF document text
    • http://zrdb-drogbud.pl/Upload/file/19490741131.pdfIn PDF document text
    • http://fzcce.com/aimgs/uload/files/puvaditulogavi.pdfIn PDF document text
    • http://georgefamilyreunion.org/clients/86186/File/78361737277.pdfIn PDF document text
    • http://kasargod.net/uploads/file/wikulevexujovu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=similar+formats+to+pdf+in+1991PDF 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_off0000e034.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE034 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f84b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF84B 10820 bytes
SHA-256: a4dfd259d5673a27942039aa71014f5246107c3ab2d519bcb9094a22779a2199
font_02_sfnt_off00011132.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11132 19060 bytes
SHA-256: aaa2883d942d9579e553baf6c4fe75f4e620f8ffb9529708ea67a4b6f47bbcef