Malicious PDF — malware analysis report

Static analysis result for SHA-256 55774a62b64a2c45…

MALICIOUS

PDF

85.1 KB Created: 2021-09-19 00:27:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 9c650e18ab60b734749d1382aa58dd6b SHA-1: 9b1f3894fe283325af06072d2662bf46c6b6ec11 SHA-256: 55774a62b64a2c450ebf8b87c308c98ca676dc5a2aa8995eeeeb0432edd793e8
142 Risk Score

Malware Insights

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

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains embedded JavaScript, which is likely used to download and execute a second-stage payload from one of the numerous external URLs. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a large number of links pointing to potentially disposable domains, suggesting a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://celyroknaterase.sk/editor_uploads/system/files/19202147798.pdf In PDF document text
    • https://sibirprokat.ru/ckfinder/userfiles/files/jalijemasideg.pdfIn PDF document text
    • https://jotelek.hu/files/file/solotavakufoketozuwajug.pdfIn PDF document text
    • http://tourhong.com/FileData/ckfinder/files/20210912_3AD9F4226A343F18.pdfIn PDF document text
    • http://amadpich.com/userfiles/file/nubapalexanepobon.pdfIn PDF document text
    • http://web5gstore.com/Files/files/dajelep.pdfIn PDF document text
    • http://computer-rudolstadt.de/upload/file/75740920544.pdfIn PDF document text
    • https://xn--psg-9lac.hu/files/files/nipujokumebovoxas.pdfIn PDF document text
    • http://haustechnik-hagenauer.at/guronezupenofapodipu.pdfIn PDF document text
    • http://yokohama-model.com/userfiles/files/raguviwetezifimerax.pdfIn PDF document text
    • https://promise-land.com/upload/file/97679636754.pdfIn PDF document text
    • https://umutfm.com/resimler/files/96326093061.pdfIn PDF document text
    • http://blackivy.pl/userfiles/file/muzemimuv.pdfIn PDF document text
    • http://bfr-bialapodlaska.pl/userfiles/file/xewuxapazefuviroxamizo.pdfIn PDF document text
    • http://www.phsdcenter.com/temp/js/ckfinder/userfiles/files/65361116528.pdfIn PDF document text
    • https://zemiigori.com/uploads/file/ruduwosufizuzowe.pdfIn PDF document text
    • http://world-spa-resorts.com/dok/zitefujete.pdfIn PDF document text
    • http://mariamozharova.ru/uploads/files/29935525824.pdfIn PDF document text
    • https://xn--hjrnskadeakademien-mtb.se/userfiles/file/dezofeka.pdfIn PDF document text
    • https://ancoraeducacion.com/images/xevoxisupujibejujusew.pdfIn PDF document text
    • http://casaperferiesantamariagoretti.com/writable/public/userfiles/file/82346345065.pdfIn PDF document text
    • http://pxmonastery.org/CKEdit/upload/files/wemapelafite.pdfIn PDF document text
    • https://readandenjoy.ae/userfiles/files/73303987491.pdfIn PDF document text
    • https://phuketwebstudio.com/ckfinder/userfiles/files/23607768758.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=get+root+access+without+rootPDF 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_off0000e815.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE815 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001002c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1002C 10404 bytes
SHA-256: 2c2b78b9c355da8cb8417272d8cf8a5f8e08fb3b481a2ff835ae5f7332fc7879
font_02_sfnt_off000117fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117FB 17916 bytes
SHA-256: 0d1fa9183bdd36ddbd1093e2216c9acf6dba02e5acc7c4b732a229e6ad682e0b