Malicious PDF — malware analysis report

Static analysis result for SHA-256 2556c065b352f779…

MALICIOUS

PDF

86.6 KB Created: 2021-09-05 21:33:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6949f7a30fd2e100e6938e490a6d0914 SHA-1: ebb76d90ed2b17c760d71f91f4f0d2be345d16b2 SHA-256: 2556c065b352f779d1117a3f13c1664e885aed34eaa173e6171aa586971c2927
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS platforms or appear to be part of a link farm. The heuristic PDF_RANDOM_URL_LINK and PDF_SEO_DISPOSABLE_LINK_FARM indicate a pattern of distributing malicious content through these links. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to trick users into downloading further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://fmi.lu/userfiles/files/19126884131.pdf
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8c4ac6e89f---41523834141.pdf
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/d74abf5e74612b4b48f4e15a2acc4dda/manawirefeligepap.pdf
    • http://xn--365-pn7mwb654m2qn.com/ckupload/files/55869606113.pdf
    • https://arerp.kr/data/file///60597886195.pdf
    • https://advancedcheckcashadvance.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084d2c760696---21421478028.pdf
    • http://startent.ru/SITE/files/editor/file/lefemukudebujuzaxodofep.pdf
    • http://haisushitogo.com/uploads/files/17822985412.pdf
    • https://ludifrance.fr/userfiles/file/mikedijobibilirexopofivo.pdf
    • https://bf-pomosch.ru/wp-content/plugins/super-forms/uploads/php/files/k2ep31cpka8m0bpngc2svuipt4/52747545851.pdf
    • https://electrabicycles.pl/app/webroot/uploads/file/16210625336384.pdf
    • http://ghalemdi.com/userfiles/file/77899498274.pdf
    • http://safaraval.com/basefile/safaravalcom/files/8452946879.pdf
    • http://bougerpourstarlight.ca/clients/c/c6/c668404594a1c08d975ab50c7bec58f6/File/26609519941.pdf
    • http://carraracucinecomponibilitrapani.it/userfiles/files/21799279546.pdf
    • http://joinsocialbubble.com/cake/beta/userfiles/file/35079320764.pdf
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/8ce2f2faa6a9c361c873aafbbe1dd992/wurotoji.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fbeca4467b4---gajiki.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abab32290fe---96348130284.pdf
    • https://home18.ru/wp-content/plugins/super-forms/uploads/php/files/14a3a2bcf136df3f35e885dce529a4a1/fomiz.pdf
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b67cd505c96---fuzelozeputoxodoladufape.pdf
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611687875ba8c---39297129351.pdf
    • http://sieckultury.pl/wp-content/plugins/super-forms/uploads/php/files/55dd63e339f324a9b3cb33db4080caa7/jixabavipiladirazabigi.pdf
    • https://imagebuzz.net/ckfinder/userfiles/files/84245899621.pdf
    • http://stavebnevyrobky.sk/www/upload/files/55270822265.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=moral+stories+in+english+for+adults+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_off0000ecef.bin
026d328d4de516e0fc3b22fb5d75a874d1f7f94cac988087511200097a4777d8
pdf-font-stream PDF embedded font (sfnt) at offset 0xECEF 18056 bytes
font_01_sfnt_off00011bbf.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11BBF 16792 bytes
font_02_sfnt_off000133d6.bin
578dc4ed803df185c41c8ead29c9e24a5590d3811f0d352e8927d35c97a8591f
pdf-font-stream PDF embedded font (sfnt) at offset 0x133D6 10872 bytes