Malicious PDF — malware analysis report

Static analysis result for SHA-256 637bbccac90be9d9…

MALICIOUS

PDF

91.4 KB Created: 2021-07-01 20:51:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-17
MD5: 06b463641edc1b89a22170b91febf4ba SHA-1: e7b6414e3bd1db6918c56debf28479997b1e66ac SHA-256: 637bbccac90be9d9b3a527137bb6bdda56376974169de15ac590ae59c6faeafd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF 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 potentially compromised or disposable domains, suggesting an attempt to redirect users to malicious content. The presence of numerous URLs, many pointing to WordPress form upload directories, reinforces this conclusion.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070cfb0eaa01---4784915379.pdf In PDF document text
    • https://neoville.ru/wp-content/plugins/super-forms/uploads/php/files/fe92a707b33a098fe7cda8630cba70b2/60844351076.pdfIn PDF document text
    • http://makaeximworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d6b2b3ffbb---duwiwanujekobarolojojadin.pdfIn PDF document text
    • http://myucmas.com/userfiles/file/14880298783.pdfIn PDF document text
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/160782f6fca5a0---jolijibetexesezas.pdfIn PDF document text
    • https://asigurareingermania.ro/wp-content/plugins/super-forms/uploads/php/files/1ghd0up5dfv289mvq0apd114m4/58258309173.pdfIn PDF document text
    • http://sbhs1967.com/clients/8/89/8985ce50e7417da620f75e2af787291b/File/27103824013.pdfIn PDF document text
    • http://midel.me/userfiles/file/62917109129.pdfIn PDF document text
    • http://freeski.hu/freeski/file/39823119451.pdfIn PDF document text
    • https://novamakine.com/upload/ckfinder/files/gavogofobadebevenojas.pdfIn PDF document text
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/bfbf4f346c4de8d2bf1c950921d4b41b/38413865336.pdfIn PDF document text
    • http://parkwestresidences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bc3eb348cd---jixejuvujevebexun.pdfIn PDF document text
    • https://apc-algercentre.dz/ckfinder/userfiles/files/zagiwulikofojavuf.pdfIn PDF document text
    • https://www.popcaffe.it/wp-content/plugins/super-forms/uploads/php/files/44041c8c2533254be9036f2df214d7cf/27440855441.pdfIn PDF document text
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b0cfd93cfa0---xuwexapovumakixof.pdfIn PDF document text
    • http://cokhixnktientien.com/Images_upload/files/feforikefapexabubo.pdfIn PDF document text
    • https://www.swx.global/wp-content/plugins/super-forms/uploads/php/files/d1d2834959db550d8b6c877f17934867/tuxumas.pdfIn PDF document text
    • http://allamericannursing.com/userfiles/file/45441345530.pdfIn PDF document text
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/d23b1f19a88eb803ba84e291edde3109/70711387385.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c574c0ad42c---3489370066.pdfIn PDF document text
    • http://animationcoach.com/userfiles/file/tawunajularokezijunanit.pdfIn PDF document text
    • http://cocoal.com/uploads/file/71082907518.pdfIn PDF document text
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083750499a9b---15257120490.pdfIn PDF document text
    • https://thejasmineway.net/wp-content/plugins/super-forms/uploads/php/files/bbc3e19eitis798tvfrllsevos/52410677292.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=free+naked+pictures+of+older+womenPDF 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_off0000fd90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD90 11036 bytes
SHA-256: 2f4a5737f1c34b8dc0fe8e1cbc0b58947416b4e81bff7a9785cba7652329c61f
font_01_sfnt_off0001173f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1173F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012f51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F51 19204 bytes
SHA-256: 49007ef9ec3ef0309205e1709f1c6302593f47071abc79501f1ed272c3e66371