Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f6a09a61cf25813…

MALICIOUS

PDF

91.8 KB Created: 2021-09-03 21:28:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b24f6fa1db747d0e0ad0a17a2f341ed4 SHA-1: 06d1007e66c000c16d5921138aa7987a6ecd133f SHA-256: 4f6a09a61cf25813284f07b881141c9fe95c693cb5c4b9087e6418abce0e3099
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to multiple compromised websites and disposable hosting, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and heuristic firings are consistent with techniques used to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9913

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://harkakotony.hu/UserFiles/file/23454112447.pdf
    • https://nstoplana.rs/ckfinder/userfiles/files/kuwoz.pdf
    • http://nc2e.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160860ffbe0d80---92282961852.pdf
    • https://elearning-chemistry.ro/userfiles/file/51942813784.pdf
    • http://vitalchurchesinstitute.com/files/file/kepulevifovulufimus.pdf
    • https://dianthusindustrial.com/resimler/files/juxikulit.pdf
    • http://smolensk-bakaleya.ru/userfiles/file/nibifawedarisulepusim.pdf
    • http://firanywiktoria.pl/uploads/editor/file/sulokosizebudu.pdf
    • https://elsa-daulte.com/ckfinder/userfiles/files/bofenafarine.pdf
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/16089922e154ca---kigisosakobupuma.pdf
    • http://ustunongel.com/image/files/xomawapakupupuxasiwa.pdf
    • http://ubest.ru/images/file/17062339312.pdf
    • https://systematix.pl/userfiles/file/1346549097.pdf
    • http://www.idenet.net/wp-content/plugins/formcraft/file-upload/server/content/files/160bfbe0c2ddbc---21538468481.pdf
    • https://clumba-indoor.ru/files/files/dimawatalodemal.pdf
    • https://www.vedaaz.com/wp-content/plugins/super-forms/uploads/php/files/3f95abff83e40f4551a248ca43b76160/56270877336.pdf
    • https://acronimocostanzo.com/userfiles/file/95725308841.pdf
    • https://rodolphe-blanchet.fr/Rodolphe/fckeditor/file/88249389422.pdf
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/e307663a5eb9ebb956a82d0a6c6f0f47/bewumaribekavakuba.pdf
    • https://aedwea.com/upload/foto/xoseparepowapozabag.pdf
    • http://automsystem.com/UploadFile/file/20210502165331338.pdf
    • https://masterjobintl.com/ckfinder/userfiles/files/wibifafalemexibekigotobe.pdf
    • http://krikrik.ru/uploads/ckfinder/files/welesoruketemasavafuvik.pdf
    • http://icmasistemas.com/userfiles/files/kuvisuxitijukozifuxere.pdf
    • https://congchung7.vn/upload/file/vosazasegol.pdf
    • http://architettobotteonpierpaolostudioabacus.it/userfiles/files/81437380546.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=proton+iriz+service+manual
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fd1f.bin
292b3f91033e7a65626505c4fadd0706f7b318766d91b055c3cf44fb5045ab87
pdf-font-stream PDF embedded font (sfnt) at offset 0xFD1F 10616 bytes
font_01_sfnt_off0001157b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1157B 16792 bytes
font_02_sfnt_off00012d8d.bin
c76dcb01568c957e771d32206a429196576a7967b9d2707313a40fcf50068b8d
pdf-font-stream PDF embedded font (sfnt) at offset 0x12D8D 19216 bytes