Malicious PDF — malware analysis report

Static analysis result for SHA-256 5ff3817e9a64a52d…

MALICIOUS

PDF

87.5 KB Created: 2021-10-05 20:35:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 60cf018de07eff2d89a4893672207c7b SHA-1: 9475e4070210fb5d6437a812a03bacea6180a3f3 SHA-256: 5ff3817e9a64a52db979c7cd0c6be71189999b1bbe9ae95b6f462ac9e3ff2168
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, with heuristics indicating it functions as a link farm and potentially a fake invoice lure. The embedded URLs, many hosted on compromised CMS upload storage or disposable hosting, suggest an attempt to redirect users to malicious sites. While no scripts were explicitly extracted, the PDF structure and link farm behavior are consistent with phishing or malware distribution tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 7

  • 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.
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators
  • 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://martom24.pl/martom/userfiles/file/tejisomaginerowuxolufixav.pdf In PDF document text
    • http://vet-arrighicolangelicristilli.eu/userfiles/files/65624301466.pdfIn PDF document text
    • http://divodizain.ru/ckfinder/userfiles/files/15946600961.pdfIn PDF document text
    • https://khachsan295doson.vn/namthuan/images/news/files/1822847651.pdfIn PDF document text
    • http://rdasesores.gestconcursal.com/editor/ckfinder/userfiles/files/22231249808.pdfIn PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132af4ac47fd---68793457845.pdfIn PDF document text
    • http://hexindechem.com/upload/files/bigotimilatesamagexomawu.pdfIn PDF document text
    • http://popnmusic.fr/userfiles/file/zaziledawenasapigilubimaj.pdfIn PDF document text
    • http://ppfi-online.com/userfiles/file/41427113753.pdfIn PDF document text
    • http://diagonal.org.ar/wp-content/plugins/formcraft/file-upload/server/content/files/161365760a5a3a---bugizubufiwofoturos.pdfIn PDF document text
    • http://www.prodomasa.com/ckfinder/userfiles/files/miwetalobowopixexabiruwi.pdfIn PDF document text
    • http://carmakers.cz/userfiles/files/2485895517.pdfIn PDF document text
    • https://kaktutzhit.by/uploads/files/sopopopurezogirafuriv.pdfIn PDF document text
    • https://pima-alarms.net/slicice/file/69896023619.pdfIn PDF document text
    • https://www.stnedu.com/ckfinder/upload/files/40510743906.pdfIn PDF document text
    • https://chief-moving.com/editor_upload/file/30542224439.pdfIn PDF document text
    • http://calisnt.com/uploads/files/28192867141.pdfIn PDF document text
    • https://cvenhancer.com/wp-content/plugins/super-forms/uploads/php/files/071c2bc5299f2bd3dc64f60d6dc3dafd/tonedubik.pdfIn PDF document text
    • http://nature-revive.org/files/file/68868921338.pdfIn PDF document text
    • https://xistenze.nagydavid.com/files/files/82800053903.pdfIn PDF document text
    • http://photou.cc/ckfinder/userfiles/files/1639359740.pdfIn PDF document text
    • https://schodyperfekt.pl/user_upload/file/3378308676.pdfIn PDF document text
    • http://machinegroup.ru/img/outer/files/839660318.pdfIn PDF document text
    • http://cetinelektrik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/161558a2472905---4924423809.pdfIn PDF document text
    • https://khyatiinfotech.biz/ckfinder/userfiles/files/rejademulu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=federalism+definition+governmentPDF 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_off0000edd5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDD5 19532 bytes
SHA-256: a8ed23c22e3ba8f89f385c7af04716c9c5f572ff934850d135e7d8c331123393
font_01_sfnt_off00011fbf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FBF 10740 bytes
SHA-256: 120a099ad80b95a598928e9f52bb3c342c701087920c847cd56c4302e5ed72d5
font_02_sfnt_off00013835.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13835 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1