Malicious PDF — malware analysis report

Static analysis result for SHA-256 b636fdddda525d4c…

MALICIOUS

PDF

104.9 KB Created: 2021-07-22 02:27:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 73d722a90b59046f1f282c493c556058 SHA-1: 9a360990f92aa61ba02eb5b3baeb9c4f8a00198d SHA-256: b636fdddda525d4ca12c89fc5bda8875fa59b3baf2cdcbc1b6143d66d4789183
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous external URLs, many pointing to compromised CMS uploads or disposable domains, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. No scripts were extracted, and the document body was unreadable, but the heuristic firings clearly indicate the document's purpose is to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9859

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://penzionradvanice.cz/res/file/35967352778.pdf
    • https://parokisantolukas.org/Uploads/userfiles/files/7631684672.pdf
    • http://jointrilogy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160922a1cdca6b---geneduvunexotoveke.pdf
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160907467a1b18---30947492413.pdf
    • http://www.zywawiara.pl/pliki/wisefititip.pdf
    • https://monyetjoget.com/contents//files/24780957285.pdf
    • https://frontlinetherapist.com/wp-content/plugins/super-forms/uploads/php/files/ccf2703116b53b1ecf4db2bc3d4049c1/57941323440.pdf
    • http://cosonhuath.com/hinhanh_fckeditor/file/91358481021.pdf
    • http://windmill-bv.com/userfiles/files/4885757194.pdf
    • http://tragiaocolamsapa.com/userfiles/image/file/18928615939.pdf
    • https://414movement.com/wp-content/plugins/super-forms/uploads/php/files/61c544f6883691e15fa8e99885805a46/nutuv.pdf
    • https://www.vbclighting.com/wp-content/plugins/super-forms/uploads/php/files/508a66e3d168cdc65dfb836e615652f3/13321331980.pdf
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c49203d6e4c---2921023680.pdf
    • http://xn--80aaa1acmiejxr6d7fg.xn--p1ai/data/files/mevanekebukumusawa.pdf
    • http://www.circoloaletrium.it/wp-content/plugins/formcraft/file-upload/server/content/files/160d72166eab25---tupaguwodixiregife.pdf
    • http://avgdesign.com/userfiles/file/karokodadoruzalapex.pdf
    • http://flooroverstock.com/admin/userfiles/file/nubulolex.pdf
    • https://pypconsultores.mx/userfiles/file/xagubajesi.pdf
    • http://ei-windykacja.pl/upload/file/janafupulisonanuxivazuk.pdf
    • http://sochistandart.com/ckfinder/userfiles/files/bedoza.pdf
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/160862e58ae2ac---pukidarimo.pdf
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/cfaa3b971aac5fef461457fdf3c83539/mufexekisaxijodatapono.pdf
    • http://zafirkort.com/uploads/files/besajonakujorebogagimefi.pdf
    • http://veterinariacasettamattei.it/userfiles/files/rekokawesepiliruv.pdf
    • https://aawyx.com/sites/default/imageuser/file/59368150837.pdf
    • http://lhdrum.com/User_File/UpFile/file/20210709112443_a2lqdXRvc3U=.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=learn+the+korean+alphabet+hangul+from+a+to+z
    • 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 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011249.bin
db5123c43135f6d07777219a27832ebc3f7a577feeb07de847fd9d2d8f186e73
pdf-font-stream PDF embedded font (sfnt) at offset 0x11249 10892 bytes
font_01_sfnt_off00012b0e.bin
9f9c9255c0426c77c5b13ef22f4242f4f7095bfd8ba808a20cf1712cd58ffb40
pdf-font-stream PDF embedded font (sfnt) at offset 0x12B0E 16236 bytes
font_02_sfnt_off000140a8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x140A8 16792 bytes
font_03_sfnt_off000158ba.bin
c1805db37e514a0af2d7b12ccb4453038065f83c4b8c39da3ef00b419be01378
pdf-font-stream PDF embedded font (sfnt) at offset 0x158BA 17220 bytes
font_04_sfnt_off00018556.bin
9743a8a4fab56d645edb42eda326691bc0868c02ee33ada9c01d90e0adbcefd4
pdf-font-stream PDF embedded font (sfnt) at offset 0x18556 3896 bytes