Malicious PDF — malware analysis report

Static analysis result for SHA-256 c595d74767af2a81…

MALICIOUS

PDF

84.7 KB Created: 2021-07-18 10:56:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: ac39073a7d0e1f869156ca4a917f25ae SHA-1: ba37611ce61399947578cad60e47e16323458be7 SHA-256: c595d74767af2a812bf839f99b9851c06633e5e475e281c54e4149863f4201f9
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links to external websites, many of which are hosted on compromised WordPress sites or disposable domains, indicating a phishing or malicious redirection attempt. The ClamAV detection and ML classifier strongly suggest malicious intent, likely to lure users to malicious content or downloads. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL heuristics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/b62b7ac45bfeb302cd3bac093e67a0a1/74547632556.pdf In PDF document text
    • http://thm-holding.ru/wp-content/plugins/super-forms/uploads/php/files/5439174f58faeeaf95e6bb6cd51c9895/55954470935.pdfIn PDF document text
    • https://foodvellythailand.com/upload/files/noxuxi.pdfIn PDF document text
    • https://www.digitalsofts.com/wp-content/plugins/formcraft/file-upload/server/content/files/160873d75185b8---gitadolagu.pdfIn PDF document text
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/elpujdarl83162kkaa9o33je72/52942980739.pdfIn PDF document text
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081088b3a875---82524369240.pdfIn PDF document text
    • https://tocgia247.com/wp-content/plugins/super-forms/uploads/php/files/bldrev6ldvg1g88cnc8h5h0dfq/vulorivepiweruva.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a8d940e8cc5---61126120248.pdfIn PDF document text
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/umrets8d2oaval12o0v3mf5gc0/43453736253.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/16090fcc6be14b---zoriwadimev.pdfIn PDF document text
    • http://www.dismaplant.com/ckfinder/userfiles/files/5066163738.pdfIn PDF document text
    • http://woodwork.pl/ubezpiecz/obrazy/file/gepotalobi.pdfIn PDF document text
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082845f5fc31---winefododakelozuz.pdfIn PDF document text
    • https://advancedbusiness.co/wp-content/plugins/super-forms/uploads/php/files/6d2d3d5acdca8e197ffb99ad61d7d9ae/15364049923.pdfIn PDF document text
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/ba4f19c13edc5c8845a4869b62fd85bf/91254963486.pdfIn PDF document text
    • http://teormech.ru/teormech/usrimg/file/savanezis.pdfIn PDF document text
    • https://flyags.com/editorResources/file///69136560185.pdfIn PDF document text
    • https://aashianarealty.com/file/jinebigogon.pdfIn PDF document text
    • http://cayxaotamphan.net/userfiles/image/file/7090751902.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083b07257c2e---67627792469.pdfIn PDF document text
    • http://reversetheclocknow.com/ckfinder/userfiles/files/96382651221.pdfIn PDF document text
    • http://www.oteliapelsin.ru/ckfinder/userfiles/files/mamadejijotedu.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/0c1d46bd90b26a848f3cf7290b4fc178/mukugiwisixotozazupago.pdfIn PDF document text
    • https://hkparkkonutlari.com/image/files/nepilufebazo.pdfIn PDF document text
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/c9feuusbo0o17uejjeoedunb7r/jumifewavidanifekorebilej.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=meaning+of+llb+in+law+degreePDF 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_off0000eb9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB9A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000103ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103AC 16344 bytes
SHA-256: eb341f1ff8557ba4064bb03ab987fdcf02dbb041c0649248f3a1c3af53b9fcc0
font_02_sfnt_off00012df9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DF9 10480 bytes
SHA-256: e52b59e914a993ad6b4e33c9b46fae4bf184a4324cdc3b0661fb279d6763abdf