Malicious PDF — malware analysis report

Static analysis result for SHA-256 66c88d06aeef3b42…

MALICIOUS

PDF

144.0 KB Created: 2021-07-01 21:41:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 077a56c7aa61f0bc5df59462163e6194 SHA-1: 31017e003c9e58982f7052b5e4a3ef1af91fae6a SHA-256: 66c88d06aeef3b42aaa0b49514e86501584bf521ec61eed976f85c8945f39321
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm hosted on compromised CMS uploads, with numerous distinct hosts and UTM parameters suggesting a phishing or redirection campaign. Although no scripts were extracted, the PDF structure and embedded URLs point towards a social engineering attack, likely spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9376

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/16094d8d5916d1---95139842693.pdf
    • http://bagiez.de/userfiles/file/58498751721.pdf
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609cffb41325d---xonijipovaz.pdf
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16072f0538ebdb---53844540630.pdf
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606e4acf5314d.pdf
    • http://bazatalty.pl/wp-content/plugins/super-forms/uploads/php/files/33e595ca6efbbbec0f26c0822bb0e344/77705180130.pdf
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/3d82cda1e97c2d094a12f78603121a28/68776151318.pdf
    • http://stardentalcare.org/userfiles/file/dixavigeruwulagabe.pdf
    • http://cncforginghammer.com/d/files/99661024278.pdf
    • http://vasilii-orlov.fun/wp-content/plugins/super-forms/uploads/php/files/b7b279ca69c8de3135c29e614bfa775d/3032229637.pdf
    • https://xlspandoek.nl/userfiles/file/7103923581.pdf
    • http://izdepskifamily.com/clients/1/1a/1adacdf247316bc4617b3617d965acc7/File/25269414153.pdf
    • http://www.canadavisaservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d41d47655b---bozate.pdf
    • https://jollytime.ru/wp-content/plugins/super-forms/uploads/php/files/62644870df83201caf34224528dba1a7/tasopijifuk.pdf
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bde35a09ea9---popuwuxuxalaxofajudines.pdf
    • http://ildongwire.com/userfiles/file/56083785059.pdf
    • http://www.ponderosafestival.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082039031583---15329383051.pdf
    • http://faw-asia.com/image/upload/files/5419839499.pdf
    • http://meandnetworking.com/ckfinder/userfiles/files/venogavanemikux.pdf
    • http://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/160812bf08ca97---23844176972.pdf
    • https://stehovani-ostrava.cz/static_pages_files/file/dewidaw.pdf
    • https://dgaspcsm.ro/ckfinder/userfiles/files/79752238526.pdf
    • http://associacaoguainumbi.org.br/wp/wp-content/plugins/formcraft/file-upload/server/content/files/1606fd161ce5dc---65977445290.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=jungkook+and+rm
    • 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 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00017a14.bin
f453ea4b670a7665a999be156b7fb9a120a76802d039b4eb15f8f458a72757ec
pdf-font-stream PDF embedded font (sfnt) at offset 0x17A14 10240 bytes
font_01_sfnt_off000190d1.bin
2692517d5dea3635d2f027e98b139e5c75f37eb77ac11218c2ddcb2db1f0f334
pdf-font-stream PDF embedded font (sfnt) at offset 0x190D1 32260 bytes
font_02_sfnt_off0001d0fa.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1D0FA 16792 bytes
font_03_sfnt_off0001e908.bin
fcdb85a80a9e45d7134d1f63de50f05114872148345c237107e86b096e37fff0
pdf-font-stream PDF embedded font (sfnt) at offset 0x1E908 16860 bytes
font_04_sfnt_off00021a55.bin
e456fec5953656cc52705a962b681d07ac9180ff0253770264bd8da0e8caf90b
pdf-font-stream PDF embedded font (sfnt) at offset 0x21A55 16316 bytes