Malicious PDF — malware analysis report

Static analysis result for SHA-256 1cb2087f3d504ade…

MALICIOUS

PDF

85.2 KB Created: 2021-06-08 21:03:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-04
MD5: b27355d9af427278fad2f5c1d1f486be SHA-1: 6d8a4aa0daad005ee9d5fbd5f5adfd97a75bd7f3 SHA-256: 1cb2087f3d504ade1491d669dd9fd5d2a004a1f949c6044b42f9f783468e142e
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 0.9996

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://drafthe.ru/uplcv?utm_term=english+grammar+in+use+elementary+download PDF link annotation
    • http://www.pianoszimmermann.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16075042c26c24---54571955963.pdfIn PDF document text
    • https://carstenrath.com/wp-content/plugins/super-forms/uploads/php/files/lu68fb3c0gn4eb1b1h23dudv09/92175229240.pdfIn PDF document text
    • https://www.ptlittleflower.org/wp-content/plugins/super-forms/uploads/php/files/8uv7l7o6novni6adk3jkap8qpu/76988548103.pdfIn PDF document text
    • http://www.barankayalar.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1607271ba1e960---rewukomejikafeja.pdfIn PDF document text
    • http://andlupa.com/userfiles/file/87560712615.pdfIn PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/1m3v0rt9ehpakj0o0n7rr5keib/rudivedidid.pdfIn PDF document text
    • http://www.tecnotrefg.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b9c782e6d37---fakilozije.pdfIn PDF document text
    • http://abacusnancy.com/userfiles/file/45360891289.pdfIn PDF document text
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b0917830761---bijejibanamapimuzo.pdfIn PDF document text
    • http://slsnn.ru/content/file/8839406616.pdfIn PDF document text
    • https://gofropack.com/wp-content/plugins/super-forms/uploads/php/files/dc1bab740cef8980ced2f10963965c31/wojurolelavezakaw.pdfIn PDF document text
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609085366e942---rupalokidulujemineja.pdfIn PDF document text
    • http://maidnheaven.com/wp-content/plugins/formcraft/file-upload/server/content/files/160716bf6e0af8---wukitutonagurapefeg.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • http://janyska.home.pl/_mjanyska2013/fotki/file/7815821632.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://scripts.sil.org/OFLIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e27c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE27C 5272 bytes
SHA-256: e025d29ea9fb13c3d50afa6343a526600bafd34040cc7ea5b0512eaffe207327
font_01_sfnt_off0000f449.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF449 20496 bytes
SHA-256: fdb37a2862ee5ced92c6be23a8c94fed6a5df6fa11f50c6a0df7dabd89f427e8
font_02_sfnt_off00012329.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12329 16068 bytes
SHA-256: 9e1271d681207e96fe60c94df920a27091a957dc81e2614e9e6235263a34fce6
font_03_sfnt_off000137cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x137CF 4324 bytes
SHA-256: 9f355172d696dda274cac500966718f112ce76951f19577ac4888987ea6471b2