Malicious PDF — malware analysis report

Static analysis result for SHA-256 436d4770fadb7e1f…

MALICIOUS

PDF

81.5 KB Created: 2021-09-17 10:02:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b653bd656ec062a2aaae2a43b0a6d31a SHA-1: 89de5f7ca28a3ded0e36b44a6c0024ad6540d761 SHA-256: 436d4770fadb7e1fba5ffb07cbf424ea2267bb2a522646e7fe1e21713cbceaa2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous links to potentially compromised or disposable hosting sites, indicated by heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM'. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and embedded URLs point towards an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 http://mcrlclient.gilcom.ro/ckfinder/userfiles/files/rabasefopugem.pdf
    • http://computer-rudolstadt.de/upload/file/86448160764.pdf
    • https://tidurmalam.com/contents/files/58080645252.pdf
    • http://www.octopus-quatuorvocal.com/ckfinder/userfiles/files/85406595951.pdf
    • http://xn--e1aaafipco3bk8gra3b.xn--p1ai/upload_picture/file/renekorigadaluruw.pdf
    • https://cabsfromheathrow.com/userfiles/file/vuxogasafazoparo.pdf
    • http://xn--22cjbbm2eyae3ehabdb4kqdtae3dxnnc1fhf.com/user_img/files/7238111397.pdf
    • http://njchemland.com/upload/files/zadulasafawu.pdf
    • http://cachnhietcacham.vn/Images_upload/files/nuvumilavadomevexem.pdf
    • http://druckmaschinenservice.com/uploads/fce/files/85361826107.pdf
    • http://eamenfaraz.com/cache/fck_files/file/sapofovakiwetube.pdf
    • http://apsons.eu/files/file/gapazegotudutevikono.pdf
    • http://elmiraclassiccountry.com/wp-content/plugins/super-forms/uploads/php/files/18a6744961e5645ff04f3370d2c05447/lokagakozemosabiboza.pdf
    • https://hobbypet.cz/files/file/gofipepit.pdf
    • http://klick-tipp.at/ckfinder/userfiles/publics/files/safelemosivejizesape.pdf
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613064f89e719---38492693259.pdf
    • https://icon-studios.com/userfiles/file/waviw.pdf
    • http://change4best.ru/upload/file/sozonowosexavasuwazupegex.pdf
    • http://cofetariafraguta.ro/UserFiles/file/4034131168.pdf
    • https://projektovanje.info/userfiles/file/giradipowujaxo.pdf
    • http://sm.ac.th/ckfinder/userfiles/files/13455730193.pdf
    • https://bya-ingenieria.com/ckfinder/userfiles/files/babogidezonajerodajojumew.pdf
    • https://gpagroup.in/wp-content/plugins/formcraft/file-upload/server/content/files/16137c6c23bec2---lidivonutiseke.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=html+and+css+tutorial+for+beginners+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_off0000daab.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDAAB 16792 bytes
font_01_sfnt_off0000f2c2.bin
410aac1015d64892f8cd7dff4025ced1f1a05912c3a8320a5da390242b8c364a
pdf-font-stream PDF embedded font (sfnt) at offset 0xF2C2 11196 bytes
font_02_sfnt_off00010c73.bin
bc86d72bf49033225bcd3f7cbec5a059e1ae1a5f15a73849e199fe15e9cd273a
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C73 16996 bytes