Malicious PDF — malware analysis report

Static analysis result for SHA-256 003c64133ad8db45…

MALICIOUS

PDF

72.9 KB Created: 2021-05-26 03:59:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d1df2ffcbc974b5fa0b314ba153248a8 SHA-1: 6799161806cd9f903c025f45ccb5016db86e1dd8 SHA-256: 003c64133ad8db459f69f177930e748d56bbb8f7cef64a880013c984cd5c9350
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was detected as malicious by ClamAV and an ML classifier. It functions as a link farm, directing users to multiple external URLs, some hosted on compromised CMS uploads or disposable domains. The document body, though heavily obfuscated, suggests a lure related to 'worksheet answers', likely to trick users into clicking the embedded links. No scripts were extracted, but the PDF structure and URL patterns are indicative of a phishing or redirection campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://51-lq.com/userfiles/file/%5C/10430733690.pdf
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/ufu8q6emvcigin9l4thfanndu5/biparezufako.pdf
    • https://jnfarley.com/wp-content/plugins/super-forms/uploads/php/files/mujtfjhn29c9uvs7mrq1hjsp02/22823395122.pdf
    • https://www.audioclinica.pt/wp-content/plugins/super-forms/uploads/php/files/sn6r3ko1foakqfee660a8jrjv2/zaperiwajovarejojorovomek.pdf
    • http://mg001.cn/upload_fck/file/2021-5-12/20210512032628734164.pdf
    • https://www.emma-solutions.de/wp-content/plugins/formcraft/file-upload/server/content/files/16093a16f229e1---jixokeduxipuxewulomigu.pdf
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ed5c17b708---zesuvukeke.pdf
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607e4ccaddcbe---zinokipag.pdf
    • https://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/0i312v34bns19l14vqeo2159p0/fekejenasugagelozegubok.pdf
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075f48a06505---58733155146.pdf
    • http://stylist.in.ua/wp-content/plugins/formcraft/file-upload/server/content/files/160965d4ab0a44---5060591745.pdf
    • http://amandatravel.com/userfiles/file/sabosulebosavubisad.pdf
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/16071db26019aa---sivoxobikiralowejuxarudu.pdf
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/160900ebfb8e8d---xomujejijamoso.pdf
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/h2me8s3slk9cqb175auii4k5ev/90790637268.pdf
    • https://getlovebooks.com/wp-content/plugins/super-forms/uploads/php/files/9b5f45fa9ff7ca5926a4f00868ef1a72/80788444952.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=writing+equations+of+parallel+lines+worksheet+answers
    • 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://scripts.sil.org/OFL

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d23d.bin
dc1a77ca358a2d31108072e9a55b442e18e42d1e3ace554707fadf9f7283cb11
pdf-font-stream PDF embedded font (sfnt) at offset 0xD23D 5340 bytes
font_01_sfnt_off0000e47b.bin
14e13d347d0ad789a3a5bd4905f6a19e31e95bdc8ec8dd12e89092d3bce33540
pdf-font-stream PDF embedded font (sfnt) at offset 0xE47B 10484 bytes
font_02_sfnt_off00010822.bin
05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176
pdf-font-stream PDF embedded font (sfnt) at offset 0x10822 4324 bytes