Malicious PDF — malware analysis report

Static analysis result for SHA-256 67a88e638b957d6b…

MALICIOUS

PDF

86.8 KB Created: 2021-09-01 07:03:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2ba97e8d185fbb7d2da39183b39fdc9b SHA-1: 409e3af8d700a6dd0772de847293193ffb83e1aa SHA-256: 67a88e638b957d6b758fc2afc94a2d35123e6a88f74e2d743be421d8ff9eba2b
164 Risk Score

Malware Insights

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

The PDF contains a link farm hosted on multiple compromised websites, directing users to download files. The presence of a 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic and numerous unknown reputation URLs indicates a deliberate attempt to distribute malicious content. ClamAV also detected this file as a 'Pdf.Phishing.Trojan'.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://yugang360.com/upload_fck/file/2021-8-12/20210812194224946486.pdf
    • http://x04ydivan.ru/userfiles/file/soxonibazasorolirod.pdf
    • http://asahiru-ban.com/files/files/baworajupapazave.pdf
    • http://www.sempresaude.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606d143168e51---watirisava.pdf
    • http://esoftland.com/userfiles/file/77464741193.pdf
    • http://popmetre.com/news/files/59681140514.pdf
    • http://neodentpetrosino.it/userfiles/files/71334288844.pdf
    • http://neoneofitou.com/ckfinder/userfiles/files/69254924818.pdf
    • https://www.booster-p.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c65e5cb78d---gifikosuranulolopin.pdf
    • http://tecsun-moscow.ru/docs/file/97703197888.pdf
    • http://prttour.ca/FileData/ckfinder/files/20210616_B58D2AD905775575.pdf
    • https://realestateconnect.us/wp-content/plugins/super-forms/uploads/php/files/25nasakkmdvea34kn9l9u18ak7/wozamedodijodafekijuwej.pdf
    • https://eownauto.com/uploadpic/files/52936208034.pdf
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/160812741af7b9---89421810469.pdf
    • https://rumusjitu.com/contents//files/zitatibubudetigeputup.pdf
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/nrud4o1ken3tn6dsr739sb9ti3/56228184533.pdf
    • https://laxmigrouppune.com/wp-content/plugins/super-forms/uploads/php/files/2a507cc22c678a706f7c40f705585b7d/13603334505.pdf
    • https://medtek.vn/storage/file/ketonefilomasarobewusi.pdf
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071f6dfbc1d6---mamoxu.pdf
    • http://nnk.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160be59739137d---4974326023.pdf
    • https://rubyyadav.com/nbloom/fckuploads/file/lerariz.pdf
    • https://outsourcedbackoffice.co.uk/wp-content/plugins/super-forms/uploads/php/files/f7fa5edf9e4a205c4d7fd216c9a7578e/tewubavibalij.pdf
    • http://mgmkt.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1610eda11d8de8---jerojatibi.pdf
    • http://bsa-billiard.by/images_from_html_editor/file/rimibema.pdf
    • http://cadelupo.it/userfiles/files/satadedakegobutos.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=6th+english+guide+download
    • 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_off0000ea87.bin
5f7364ab7cdf8af108180b0f064703d9145a5d662aef4fc3ffdcafdb43ddc1c2
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA87 18380 bytes
font_01_sfnt_off00011a6b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A6B 16792 bytes
font_02_sfnt_off00013282.bin
43efe7b2ffa42da3cc276712b98e6a9c6401cfdc29eb22d6178a29cd7a5e4e4e
pdf-font-stream PDF embedded font (sfnt) at offset 0x13282 10684 bytes