Malicious PDF — malware analysis report

Static analysis result for SHA-256 10b797c09b6ab46c…

MALICIOUS

PDF

68.3 KB Created: 2021-09-27 04:19:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 9ccc21170e96efe50d16578898edf26a SHA-1: 5735ae8a7cfa0c4d09d5d1227e0ba23af57dcfda SHA-256: 10b797c09b6ab46c237cff8ab4be90f50dc9295d42f485c3fb60dde36bf72b97
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample was detected as malicious by ClamAV and an ML classifier, with heuristics indicating it is a link farm and a callback phishing lure. The document body is heavily obfuscated, but the presence of external URIs and the heuristic findings strongly suggest a phishing attempt. No scripts were extracted, but the PDF structure and embedded URLs point towards a malicious intent to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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
  • 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://cructi.ru/uplcv?utm_term=trapezoidal+rule+area PDF link annotation
    • http://wxmx.cn/upload/ckimg/files/202109071850278123.pdfIn PDF document text
    • http://bakineshr.az/ckfinder/userfiles/files/damopufamibedinu.pdfIn PDF document text
    • http://girc.ncue.edu.tw/ckfinder/ckfiles/files/31419037936.pdfIn PDF document text
    • http://baovephuongtroi.com/vietkiendo/upload/file/dikijederiwerurenif.pdfIn PDF document text
    • http://m3hotels.com/userfiles/file/74092944148.pdfIn PDF document text
    • http://formel1vermietung.de/userfiles/file/75980145305.pdfIn PDF document text
    • https://laetitiabernard.fr/images/file/3105033964.pdfIn PDF document text
    • http://aimic.com/userfiles/file/96249327658.pdfIn PDF document text
    • http://matras-devison.ru/upload/file/93680020580.pdfIn PDF document text
    • http://reklamaopole.pl/userfiles/file/ninetorig.pdfIn PDF document text
    • http://movitecnic.fr/ressource/site-image/files/potikesejugirilidozetala.pdfIn PDF document text
    • http://ecohort.com/userfiles/files/47419336505.pdfIn PDF document text
    • http://thebankcardservices.com/uploads/files/91377102167.pdfIn PDF document text
    • http://www.vandiestbrandstoffen.be/uploads/files/goseneweligodorala.pdfIn PDF document text
    • https://b2bpro.xyz/userfiles/file/nezipiturizija.pdfIn PDF document text
    • https://kaxtongroup.com/home5/maxconne/public_html/kaxtongroup/assets/images/newspostimages/files/34558471592.pdfIn PDF document text
    • http://2990592.ru/ckfinder/userfiles/files/40814577767.pdfIn PDF document text
    • https://basisnomor.com/contents/files/pivonutikifawos.pdfIn PDF document text
    • https://penzion-pod-rozhlednou.cz/img/file/muputinekexafuximo.pdfIn PDF document text
    • http://massarentearchitettura.com/userfiles/files/debisuxubod.pdfIn PDF document text
    • https://ashleymongolia.mn/uploads/files/rixeniwumibub.pdfIn PDF document text
    • https://ripedzn.com/app/webroot/files/fckeditor/file/kagubosuvelibufalonapur.pdfIn PDF document text
    • http://www.mmalappeenranta.com/tiedostot/files/rizopajegulavonelavuna.pdfIn PDF document text
    • http://www.taimaobi.com/admin/ckfinder/userfiles/files/11789383707.pdfIn PDF document text
    • http://basketaci.cz/UserFiles/File/lazubawojal.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_off0000afa2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAFA2 10136 bytes
SHA-256: 61dcc25c1a2e7324a31a2722a9167c48613d984ddab1e696ce9395d6f74775ae
font_01_sfnt_off0000c651.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC651 14808 bytes
SHA-256: 866dcd61ea708779e6ef04a75a7fd1a7fc26753074ea38d15333f23bbaa4b133
font_02_sfnt_off0000ebcd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBCD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1