Malicious PDF — malware analysis report

Static analysis result for SHA-256 90a55785321c7880…

MALICIOUS

PDF

83.4 KB Created: 2021-09-19 20:11:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 521350e827eb2fd59532da2a1317b94b SHA-1: 093b7fd10e05cb265d92e2a94cef209ad76a0761 SHA-256: 90a55785321c78809df3830d87c3dbfd97a147ab63a72cb67ffe0ae2b3790672
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, with several heuristics indicating it functions as a link farm. Notably, some links point to compromised WordPress upload storage, suggesting a tactic to host malicious content or redirect users to malicious sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://krakow4you.pl/krakow/files/wapinufapakajuzomutinow.pdf In PDF document text
    • https://travelone.ae/userfiles/files/dunenuda.pdfIn PDF document text
    • https://www.aledrukujemy.pl/ckfinder/userfiles/files/tuzajotur.pdfIn PDF document text
    • http://law885995.com/upload/fckimages/file/dipojimimopubodugixonu.pdfIn PDF document text
    • http://sportsgarten.com/editorData/file/jevitosunifanonifejamix.pdfIn PDF document text
    • http://kco.su/userfiles/file/45239789949.pdfIn PDF document text
    • http://makesrealsense.com/ckfinder/userfiles/files/xezes.pdfIn PDF document text
    • https://ghadir-eng.com/userfiles/files/votesuwazitoj.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/161417f2fe928a---89750219429.pdfIn PDF document text
    • https://www.ebenisterie-burette.com/ckfinder/userfiles/files/wuvonizudurogomapafagi.pdfIn PDF document text
    • http://wirtrauenuns.ch/images/file/xevirupadan.pdfIn PDF document text
    • http://jun-travel.com/userfiles/file/xaravekoweketivurinatilex.pdfIn PDF document text
    • http://akgwealthplanner.com/crm/files/49128251397.pdfIn PDF document text
    • http://permagnet.com/upload_files/file/2109032001481830475yr9cb.pdfIn PDF document text
    • http://amadpich.com/userfiles/file/sijavadigomevaxo.pdfIn PDF document text
    • https://www.18fire.com/wp-content/plugins/super-forms/uploads/php/files/f12b218421751de06a78086cf4a62c0f/38923142795.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/nsgj1hvhi7gfeh4usfkrirkll2/tamiwipe.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161326f9e36c1e---81127228169.pdfIn PDF document text
    • https://takarasushimn.com/userfiles/files/nusifuwitekikelelovupus.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/161436cce97c01---20880135170.pdfIn PDF document text
    • https://christianboudreau.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f375e964cc---47476362327.pdfIn PDF document text
    • https://e-casainteligenta.ro/userfiles/file/sogamorazupujedeluwa.pdfIn PDF document text
    • http://gospel-pour-100-voix.com/fichiers/newsletter/file/zugid.pdfIn PDF document text
    • https://tsydesign.com/userfiles/jws/files/66198795917.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=how+do+you+earn+robux+for+freePDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e289.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE289 10476 bytes
SHA-256: d5336d350053ec0eecf27bdf851c70761719ba39209ad8633aea07cdaf427fd5
font_01_sfnt_off0000fa79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA79 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001128b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1128B 17496 bytes
SHA-256: 0286b20c4ea2db85bed4767814c70eb6a9d3a841f4c5287559fed4f3967a6273