Malicious PDF — malware analysis report

Static analysis result for SHA-256 a640cf0a8fc5df24…

MALICIOUS

PDF

87.5 KB Created: 2021-07-04 14:51:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: bd61da48fe4afa74f4c7b7b0cc560091 SHA-1: cf80b1795d1c0b730443bd1a52a0fd26ce6bb7fb SHA-256: a640cf0a8fc5df244343d408d252b39b0cb2401a01f0811c4ec9ac1c1216da45
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs that point to compromised WordPress sites, indicating a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly suggest this PDF is a phishing or malware distribution vehicle. The presence of multiple external URIs and compromised CMS upload links reinforces the malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9922

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 https://krisoc.ru/uplcv?utm_term=ph+calculation+worksheet+answers
    • https://robinio.de/wp-content/plugins/super-forms/uploads/php/files/5611dg2lueusoma080j36a33f8/24995946740.pdf
    • https://mariellatriolo.it/public/file/13429524754.pdf
    • http://raduzhniy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d379a8d245---vefesesekoduzomur.pdf
    • http://www.electricman.in/demo/frontend/web/uploads/files/51720903951.pdf
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e443d5642c---93178498919.pdf
    • https://www.lamuccacompany.com/wp-content/plugins/super-forms/uploads/php/files/1b75129610dfda437a439b533d2caf24/69297791982.pdf
    • http://pvsystreports.com/wp-content/plugins/super-forms/uploads/php/files/am808mihodtsu79l9vgrjrb2a6/felenujagimuxapedutub.pdf
    • http://passaicvalleyclassof1957.com/clients/44362/File/wixamafiruvonepokugelux.pdf
    • https://www.aserspa.net/wp-content/plugins/super-forms/uploads/php/files/f28a6olvv5i4btfkd1b43tkfss/ludazek.pdf
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609f6b4ce5290---vaxokefukenira.pdf
    • https://biothiennam.com/media/ftp/file/gakisekuna.pdf
    • https://workinhotel.com/upload/fckfile/tonejinepolitexazadebaris.pdf
    • https://www.fifatravels.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093c88a828cf---37721767458.pdf
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/16082480ccd0d7---93467770239.pdf
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2938c61d46---72728115770.pdf
    • https://expeditions-travel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d0e0fa0102---bibonafuxilusunenivumuxer.pdf
    • http://erbamedica.org/userfiles/files/nijakezupanadul.pdf
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/160b27e3685530---62833857488.pdf
    • https://hylyt.co/wp-content/plugins/super-forms/uploads/php/files/b38249a7e613195d5e16346056c520e2/44384358577.pdf
    • http://www.belladermeestetica.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609d47bf14a86---ralofunezepa.pdf
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16080caac33846---wavop.pdf
    • http://vivatbacchus.hu/files/file/93408702013.pdf
    • http://www.cheapmotorcycleinsurancepa.com/wp-content/plugins/super-forms/uploads/php/files/cct2epgu1gp098v1lqo080mgp7/zejuvifar.pdf
    • https://www.dolphinrfid.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b88ee82e37b---89515957353.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dd6a.bin
9ac73b380d8521821d706b881f12dd7c8754e466a1029bec6ceb54c687688a30
pdf-font-stream PDF embedded font (sfnt) at offset 0xDD6A 10604 bytes
font_01_sfnt_off0000f5b2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF5B2 16792 bytes
font_02_sfnt_off00010dc3.bin
fcca37035df06e555c2991ff65faa0e8497ca6423bee408ebc46b3aef925b516
pdf-font-stream PDF embedded font (sfnt) at offset 0x10DC3 16144 bytes
font_03_sfnt_off0001233e.bin
af0d0ec05b0a7fe9732d150a8ab8a60b8cf221da4c4e5cc3b586db5cb42272ac
pdf-font-stream PDF embedded font (sfnt) at offset 0x1233E 17200 bytes