Malicious PDF — malware analysis report

Static analysis result for SHA-256 e4fb4aa2d6308fa6…

MALICIOUS

PDF

82.9 KB Created: 2021-09-23 12:09:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 41bcd5320e0b2bede18ebfbed7a88ffa SHA-1: 96956ae1a7b6cddc3a9dd567081f1b4dd439d870 SHA-256: e4fb4aa2d6308fa6dea93d7e71264535ec6f6cabc08e2f43c8d3413fcc8a1130
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it functions as a link farm. Multiple URLs embedded within the PDF point to compromised WordPress sites and disposable hosting, suggesting an attempt to redirect users to phishing or malware distribution sites. The presence of numerous links and the use of UTM parameters in some URLs further support the attack pattern of luring users to external malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 https://krisoc.ru/uplcv?utm_term=see+private+instagram+inspect+element PDF link annotation
    • https://sg-design.top/wp-content/plugins/super-forms/uploads/php/files/6cb1052181dfa7d5898c4ab5025df96d/juxorurafelodekufajefo.pdfIn PDF document text
    • http://unityproductions.com/upload/files/45784042448.pdfIn PDF document text
    • http://modamoda.nl/uploads/pic_lib/file/kudikunim.pdfIn PDF document text
    • https://burragebrothers.com/demo/jolie/beta/userfiles/files/47298558049.pdfIn PDF document text
    • http://taociren.com/upload/file/210905183245228251x9wxr3s5ig0v.pdfIn PDF document text
    • https://dollarplus98.com/images/upload/files/pisulamupenokenutepasi.pdfIn PDF document text
    • https://radio-aurea.eu/files/file/57853671342.pdfIn PDF document text
    • https://eurochen.com/UpFiles/WebEditorFiles/file/33019996692.pdfIn PDF document text
    • https://ww150002.linebot.net/upfile/files/20210918122636.pdfIn PDF document text
    • http://obchodsezlatem.cz/upload/files/xejuwefenukajoruzeviwubeb.pdfIn PDF document text
    • http://deforma.it/userfiles/files/fenepemuvulizetavob.pdfIn PDF document text
    • http://topup-fight.com/ckfinder/userfiles/files/pewesobomodepu.pdfIn PDF document text
    • http://primebrokeragetx.com/ckfinder/userfiles/files/dolerilizunomigudedoxekad.pdfIn PDF document text
    • http://kengosushionlineorder.com/uploads/files/38089101214.pdfIn PDF document text
    • http://britishcytology.org.uk/ckfinder/userfiles/files/44937889765.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1614529d184fbd---90048979303.pdfIn PDF document text
    • http://bon-mar.com/fck_user_files/file/68294393080.pdfIn PDF document text
    • https://artinterior.bg/userfiles/file/61984611212.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16139eef4ba28b---7271964895.pdfIn PDF document text
    • http://www.39koratmachinery.com/file_upload/files/nerepeforipunilagaxa.pdfIn PDF document text
    • http://indexone.ru/upload/file/60348296849.pdfIn PDF document text
    • http://www.hermosabeachbungalows.com/userfiles/files/lereranebozurevijizi.pdfIn PDF document text
    • https://asztromiskolc.hu/ckfinder/userfiles/files/dorajotarafasukosubiz.pdfIn PDF document text
    • http://www.mamafoundation.cz/ckfinder/userfiles/files/jiweliwabafinusadezavi.pdfIn PDF document text
    • 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_off0000de76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE76 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f688.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF688 18100 bytes
SHA-256: 3d900b2c5cb20abf3e9c66673b194368e175ae0f127f0c36fb40c1f25d3faf6d
font_02_sfnt_off000124de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124DE 10740 bytes
SHA-256: 640d536b2141255e6936540794b07d88e65528a3abaec6c1bdacf6107e7b4962