Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4e82ccf834fc45a…

MALICIOUS

PDF

170.0 KB Created: 2021-06-30 05:56:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 793501a5d1ca3a3892a4cb3129a5b7e4 SHA-1: 320c73c625bca3421b027afed11bf838ccf963e3 SHA-256: a4e82ccf834fc45af7ddb5343782154c72dcb1fdb2ae02dc67cd373f280984c2
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF document flagged by ClamAV as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to potentially compromised CMS upload storage. The 'SE_CALLBACK_LURE' heuristic suggests the document's content is designed to trick users into calling a phone number, consistent with callback phishing or tech-support scams. While no scripts were explicitly extracted, the presence of embedded PDF objects and the ML classifier's high confidence suggest malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9902

Heuristics 7

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://psiakocky-potisk.cz/webpagebuilder/ckfinder/userfiles/files/kukuzobenuwijozexuviwute.pdf
    • http://progfin.pl/userfiles/file/39463011686.pdf
    • https://www.varishastalari.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606dbc692b3b8---72816368662.pdf
    • https://asthasupermarket.com/userfiles/file/folupavakexifimomujatono.pdf
    • https://www.sir.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16085e616704c4---mivizigunuvanuvexiriza.pdf
    • https://sailstudy.in/ckfinder/userfiles/files/76258079181.pdf
    • https://adreshosting.com/calisma2/files/uploads/valoj.pdf
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085aca89b319---wosevefujabiwe.pdf
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/837c68cf23e6608a4da3510807589ee0/93660349396.pdf
    • http://grupogmec.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b9cdfb7f687---56936206906.pdf
    • https://www.davidcosz.de/wp-content/plugins/super-forms/uploads/php/files/g9ufkq5jch2n2n34sf3q5ve8vb/87053249738.pdf
    • https://whitelightdesign.com/wp-content/plugins/super-forms/uploads/php/files/65d8d1d765c756a69512b8a547b982c2/tuwaritozadizunigubatazod.pdf
    • http://xn--80aamdqpfpr.xn--p1ai/upload_picture/8995486223.pdf
    • https://twfern.org/upload/ckfinder_temp/files/20210609145322.pdf
    • https://www.3dreamchurch.com/wp-content/plugins/super-forms/uploads/php/files/4fcf9c0952e295681b1a72c513706c10/33166016289.pdf
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1607ae6b900c78---89803541628.pdf
    • http://thehawthornnyc.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d08352da53---55647367765.pdf
    • https://www.hontoys.com.au/wp-content/plugins/super-forms/uploads/php/files/sa6o8dpd72gse3b4nbki7k08ht/kepalaxuw.pdf
    • http://topas.lt/userfiles/file/sofemifubudipemapobokopeb.pdf
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1608d5d7473dd0---20426084142.pdf
    • http://grodgolf.com/clients/f/fd/fd83fa7079552abb47853a85229f74c1/File/botuvopeledapemonabifozuf.pdf
    • https://www.fifatravels.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081dc96bfdb2---42966385437.pdf
    • http://yaqeen-eg.com/userfiles/file/susomusafu.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=ves+entertainment+system+manual
    • 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_off0002390d.bin
8435ecdc123817b919346ae4bec13976c66a15fa7525a717d3e7bcd9e6715c2f
pdf-font-stream PDF embedded font (sfnt) at offset 0x2390D 18644 bytes
font_01_sfnt_off00026aba.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x26ABA 16792 bytes
font_02_sfnt_off000282d1.bin
1ef4dc2e82c8ac4fbbb67eeda07dfbda8daadd87d980412dfc7a31d1d6f2bde1
pdf-font-stream PDF embedded font (sfnt) at offset 0x282D1 10332 bytes