Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a78c8a4977e499c…

MALICIOUS

PDF

84.6 KB Created: 2021-09-14 14:30:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 76558723283ca536654873040b0d0d82 SHA-1: e13953f1f54405743e3d7a927d15551ab5533289 SHA-256: 5a78c8a4977e499c075098da7a4be63e18ba26a5df757d41403c2810efae6eee
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a link farm pointing to numerous other PDF files hosted on various domains, some of which appear to be compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and contains no readable text, preventing a more detailed analysis of its specific lure.

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://farmaciafici.com/userfiles/files/tukozuranagunofinapaxe.pdf In PDF document text
    • https://unique-u.biz/images/uploads/file/70065906849.pdfIn PDF document text
    • http://prodottoitalia.eu/userfiles/files/6606248858.pdfIn PDF document text
    • http://miass.realxenon.ru/uploads/files/lamonezaratatufodufigedo.pdfIn PDF document text
    • https://brillimet.com/uploads/files/202109120153178832.pdfIn PDF document text
    • http://jrpst.pl/userfiles/file/sawebipudokumedowube.pdfIn PDF document text
    • https://clic-essc.ch/ck/ckfinder/userfiles/files/86519339681.pdfIn PDF document text
    • https://valubil.com/public/uploads/cms_file/cms_files/sanevatopirulerirare.pdfIn PDF document text
    • http://weifong.tw/fckimages/file/45543878287.pdfIn PDF document text
    • https://phoenixknights.co.uk/wp-content/plugins/super-forms/uploads/php/files/bf24423bf65e3db0993a96eed94f5eb0/51823515249.pdfIn PDF document text
    • http://www.fullertherapy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614068582d6a6---xedomibikebuxapot.pdfIn PDF document text
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136b82c7bf42---32207981806.pdfIn PDF document text
    • https://daulte.ch/ckfinder/userfiles/files/nakuk.pdfIn PDF document text
    • https://actorconseil.com/files/file/punutatobogepuneneleri.pdfIn PDF document text
    • http://patroha.hu/file/kutezibokinigukefumu.pdfIn PDF document text
    • https://seeyounow.net/userfiles/file/lazupu.pdfIn PDF document text
    • https://bititechnika.com/uploads/file/folujegumuvarorizat.pdfIn PDF document text
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/ba0be2b86316ebcde28fffd16ca4028c/nuxelutawezejalaninagam.pdfIn PDF document text
    • http://charivne.info/images/file/77351966913.pdfIn PDF document text
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613667b2da2f6---dugakusitalolaxo.pdfIn PDF document text
    • https://verlauf-ekb.ru/admin/ckfinder/userfiles/files/85257500348.pdfIn PDF document text
    • http://kamennykoberec.eu/editor_uploads/system/files/selalujibuvemapegedejan.pdfIn PDF document text
    • http://nousgarage.com/userfiles/file/vanijonomebi.pdfIn PDF document text
    • https://highlander-inn.com/assets/userfiles/files/turizabikaxonabotavex.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=what+do+apple+emojis+look+like+on+androidPDF 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_off0000e18c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE18C 10872 bytes
SHA-256: a8a883004542608fb4e656baff97381e0ea81c6b149e9d0029c953e0675701a1
font_01_sfnt_off0000fa6d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA6D 19104 bytes
SHA-256: 0603f405e577f1878e68d4977d5cbcdcef5211fbdb6b0dcfcc14597c6bc2f10a
font_02_sfnt_off00012bea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12BEA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1