Malicious PDF — malware analysis report

Static analysis result for SHA-256 b7a1c884fd3c624a…

MALICIOUS

PDF

80.1 KB Created: 2021-09-09 08:26:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 0ee297670ec9125dc0ff90e0e746cf5d SHA-1: d37f1551865b18ca705058b240bc840e8225ffed SHA-256: b7a1c884fd3c624a5f2ad437288782e5b55b8a9a25b01bcc8814e3d1cd9a5c31
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs pointing to various domains, suggesting a link farm or phishing campaign. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically flags the document as a link farm on disposable hosting, reinforcing the phishing or malware distribution hypothesis. No scripts were extracted, but the presence of multiple external URIs is a strong indicator of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://archism.ru/uplcv?utm_term=instalar+android+no+pc+virtual PDF link annotation
    • https://funke.be/data/file/tijukumo.pdfIn PDF document text
    • http://prodottoitalia.eu/userfiles/files/35008337464.pdfIn PDF document text
    • https://mashura.co/userfiles/files/kozasudigi.pdfIn PDF document text
    • http://franklcalabreseattorney.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/biwibumasojuwiv.pdfIn PDF document text
    • http://archiwum.wyryki.eu/admin/ckfinder/userfiles/files/78599902036.pdfIn PDF document text
    • https://stealthwindow.tw/uploads/files/202109041650255316.pdfIn PDF document text
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/4fe03447b7389a5d4b4791868528d121/jimafegofepabe.pdfIn PDF document text
    • http://macierz-grodziec.org/files/file/8838406671.pdfIn PDF document text
    • https://ratoempat.com/contents/files/85429795173.pdfIn PDF document text
    • https://irrisyst.eu/files/file/82233945210.pdfIn PDF document text
    • http://solis.altrodesign.eu/ckfinder/userfiles/files/vuwugawonatotelaj.pdfIn PDF document text
    • https://nmcs.ca/userfiles/files/42047655258.pdfIn PDF document text
    • http://andersonlawdecorah.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/naleluginaxevexi.pdfIn PDF document text
    • https://ekselantechnology.solutions/ckfinder/userfiles/files/78088551938.pdfIn PDF document text
    • https://yaslibakicisi.net/userfiles/file/piledejumixokuxaxerag.pdfIn PDF document text
    • http://dalnoboy.org/data/filestorage/upload/files/dazavibovopuwegimijimop.pdfIn PDF document text
    • https://associazionemusicaviva.it/uploads/file/45725765635.pdfIn PDF document text
    • http://jumpstart.mobi/userfiles/file/67517344279.pdfIn PDF document text
    • http://anhhieu.vn/hinhanh/file/29986300882.pdfIn PDF document text
    • https://0800-707-808.com/upload/ckfinder_temp/files/20210907082716.pdfIn PDF document text
    • https://kvzriu.org/images/file/worusoforoxen.pdfIn PDF document text
    • http://www.egymast-segito.hu/uploaded/fck/file/62166154856.pdfIn PDF document text
    • https://abzesolar.com/uploads/files/bunubu.pdfIn PDF document text
    • http://litho-and-co.fr/ckeditor/upload/files/33892898465.pdfIn PDF document text
    • http://aviafond.ru/userfiles/file/44038353999.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_off0000d470.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD470 10492 bytes
SHA-256: 50e99fe099c816fd829b594b36f35d283a064b8a7ac22057a0888f410ca20a88
font_01_sfnt_off0000ec69.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC69 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001047b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1047B 18012 bytes
SHA-256: b4af933829955780a812f47b674c0db5851af761555b106984a89e54e210c0de