Malicious PDF — malware analysis report

Static analysis result for SHA-256 c23156af1a494771…

MALICIOUS

PDF

83.2 KB Created: 2021-09-19 09:53:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: ab3fdd3523b584f557ea39eb1809349f SHA-1: c482fc3c34a6539152706cccb46da19dbe1dd500 SHA-256: c23156af1a494771c75792c5411f0175b2de25dadf178273fbaf17cd5c6a22e0
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. The heuristic analysis revealed numerous external URIs and a link farm structure, suggesting the document is designed to redirect users to potentially harmful websites. Although no scripts were explicitly extracted, the PDF structure and numerous embedded URLs point towards a phishing or malware distribution attack pattern, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • 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.
  • 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://chcial.ru/uplcv?utm_term=tachyon+vpn+apk+download+free PDF link annotation
    • http://innotack.com/userfiles/files/xuzudulenuxibug.pdfIn PDF document text
    • https://seedomoretravel.com/files/files/90437433768.pdfIn PDF document text
    • https://ratco-hardware.com/Ups/files/funogokifedimixarip.pdfIn PDF document text
    • https://floraplant.gr/FCKeditor/userimages/file/vuvuzulokeretixiz.pdfIn PDF document text
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/1614345796fea2---40786469346.pdfIn PDF document text
    • https://lufty.cz/UserFiles/files/79908337877.pdfIn PDF document text
    • https://kvgrup.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/16141b7872d221---86253656114.pdfIn PDF document text
    • http://grapes4u.ca/sites/all/sites/grapes4u.ca/files/40552484860.pdfIn PDF document text
    • https://bwawarszawa.pl/upload/file/2524127510.pdfIn PDF document text
    • https://leciv.fr/uploads/FCK_files/file/ruluxefojutoginis.pdfIn PDF document text
    • http://cambridgekapurthala.com/damana/userfiles/file/rokekelutukumapusorexagiz.pdfIn PDF document text
    • http://techcessgroups.com/userfiles/file/koxizuwabenokudiz.pdfIn PDF document text
    • https://lmetinternationalschool.in/ckeditor/ckfinder/userfiles/files/pejofugatotodiwolozujab.pdfIn PDF document text
    • http://sellmysayarah.com/userfiles/files/80567821179.pdfIn PDF document text
    • http://abwnickersonplaza.com/uploads/files/seliwebobalepazelu.pdfIn PDF document text
    • http://usairsprings.com/userfiles/file/tamogiw.pdfIn PDF document text
    • http://drukarnia-warszawa.pl/pliki/file/zufafazitopefezofim.pdfIn PDF document text
    • https://krossi.ru/images/content/files/nexodatuwigamonerulela.pdfIn PDF document text
    • http://wamaeassociates.com/images/uploads/originals/file/tugivuratafubikepuzadu.pdfIn PDF document text
    • https://tapuionoticias.com/ckfinder/files/68672372394.pdfIn PDF document text
    • https://gionggiacam.gagiongvitgiong.com/ckfinder/userfiles/files/zonazixavemabadogofexaj.pdfIn PDF document text
    • http://heathrowairporttaxi.website/userfiles/file/silubugevibu.pdfIn PDF document text
    • https://shiprapublication.com/uniformkontakt/userfiles/image/files/fejutowuv.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_off0000dcc6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCC6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f4d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4D8 19096 bytes
SHA-256: b21427139b001d2351cdeabd84d884bc01eea79b5e820dd06acc9cad71bd669e
font_02_sfnt_off00012709.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12709 10680 bytes
SHA-256: b2fb45c0f9b968753759eca8494b6e9db855dd7b395fe9d5dbbae42e980d68b9