Malicious PDF — malware analysis report

Static analysis result for SHA-256 0f4ac8e35dcc9a04…

MALICIOUS

PDF

78.6 KB Created: 2021-09-16 07:26:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 706c7ffc5834e58a04f639a85047ea8a SHA-1: 4d4a581c5363fc7f8cacf5110695f9b3aa155d2d SHA-256: 0f4ac8e35dcc9a0411ebb443d214bb2a4ad5ce403906d7672bf463f573c288f4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier indicating a high probability of maliciousness. It functions as a link farm, containing numerous embedded URLs that point to various websites, some of which are hosted on compromised WordPress installations. The primary purpose appears to be directing users to potentially malicious or phishing content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://laborke.ru/uplcv?utm_term=wiiflow+on+wii+u
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134309a4379e---30776973904.pdf
    • https://chuyennhakienvangvn.net/upload/files/53583541409.pdf
    • https://xaydungdonggia.com/app/webroot/files/images/pages/files/sigifuvoparike.pdf
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/9c00c67e79f3d413e912536b084a838d/76771348992.pdf
    • https://postelezmasivu-ostrava.cz/ckfinder/userfiles/files/45183201995.pdf
    • https://baobiachau.com/luutru/files/gabas.pdf
    • http://www.scenekunstskolen-efteruddannelsen.dk/ckfinder/userfiles/files/zunowake.pdf
    • http://talcmanagement.com/uploaded_files/userfiles/files/88852499577.pdf
    • http://studiotecnicodambra.eu/userfiles/files/lavuzidobiw.pdf
    • https://www.solucionaesp.com/ckfinder/userfiles/files/sotelenumazegipaxase.pdf
    • http://myhoteltrip.com/userfiles/file/51503473286.pdf
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16139ee76ab184---benekalodonotudod.pdf
    • https://www.thic.net/plugin/ce1/ckfinder/userfiles/files/vukififefofuz.pdf
    • http://gima.ge/admin/ckeditor/ckfinder/userfiles/files/tosuresokefuxag.pdf
    • http://wgadget.com/file_media/file_image/file/98130999847.pdf
    • http://tizianaiberti.it/userfiles/files/81113505214.pdf
    • http://111-orte.de/testarea/cwsCMSlight/media/files/69395903292.pdf
    • http://geyikkimya.com/userfiles/upload/file/wivezuvidafowuj.pdf
    • https://aukshanya.promosing.com/alpha/ckfinder/userfiles/files/zizemexoniwuteniwavov.pdf
    • https://doxity.ro/ckfinder/userfiles/files/43681580460.pdf
    • http://kaie.org/userfiles/file/20210913120354.pdf
    • http://gwtcs.org/Content/uploads/files/nufuresafadisuw.pdf
    • http://pbhdom.eu/userfiles/file/10011149253.pdf
    • 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_off0000cf27.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCF27 16792 bytes
font_01_sfnt_off0000e73d.bin
97138fcba27b2610e465d0053b6fe20f716a8a0d41022e978527aff84f96a6ea
pdf-font-stream PDF embedded font (sfnt) at offset 0xE73D 9728 bytes
font_02_sfnt_off0000fc84.bin
65dbf0a35e8ff389f791c4933b645c19e04c9de787b573a5f49bd3c190ed23f5
pdf-font-stream PDF embedded font (sfnt) at offset 0xFC84 18476 bytes