Malicious PDF — malware analysis report

Static analysis result for SHA-256 16bdcbfa9474e325…

MALICIOUS

PDF

123.0 KB Created: 2021-09-14 09:58:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: 7733fa4e5dcecb515566d67f3ccb1de2 SHA-1: 6beaa1bbe46231dff63988d3c5402887e6ba4e2b SHA-256: 16bdcbfa9474e325a5fa16edaf61be18a88817071bdd8f3ac45fe3ab46f37fa5
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains heuristics indicating it is a link farm and a callback phishing lure, suggesting it is designed to trick users into contacting malicious actors. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were directly extracted, the PDF structure and linked URLs point towards a phishing or scam campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://vcvscr.cz/www/www/fckphotos/file/zagemobifigid.pdf In PDF document text
    • https://triptoboloyfoundation.org/editorsfiles/files/dorozonanazasoluvefuwafi.pdfIn PDF document text
    • https://marikakozmetika.hu/editor_up/71446151766.pdfIn PDF document text
    • http://hk-sai.com/ckfinder/userfiles/files/58015302291.pdfIn PDF document text
    • https://bwawarszawa.pl/upload/file/48361338183.pdfIn PDF document text
    • http://airfa.it/userfiles/file/84039972174.pdfIn PDF document text
    • http://studiotecnicolamanna.com/userfiles/files/befamasirilosoxir.pdfIn PDF document text
    • http://hlqh.net/userfiles/file/20210909110917_1800712367.pdfIn PDF document text
    • http://osheamaloneynylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/pusomubejabuzaver.pdfIn PDF document text
    • http://veterinarioassociatopacinidallatorre.eu/userfiles/files/11613086210.pdfIn PDF document text
    • https://whiteplacard.com/UserFiles/file/xoribiwun.pdfIn PDF document text
    • https://egca.fr/userfiles/file/83764429909.pdfIn PDF document text
    • https://tinnituskozpont.hu/files/86130825633.pdfIn PDF document text
    • http://kfoodntea.com/dataroom/file/rijutupizubogij.pdfIn PDF document text
    • http://sinosteelcode.com/filespath/files/20210903202009.pdfIn PDF document text
    • http://letsbelegal.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/tekavupirezabikorimir.pdfIn PDF document text
    • http://oasis-inwaste.asia/files/file/dazer.pdfIn PDF document text
    • https://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f2e637a329---15791173260.pdfIn PDF document text
    • http://tc-muehlacker.de/data/tcmuehlacker/userfiles/file/vurarukemogezijixabox.pdfIn PDF document text
    • http://w-f-l.de/user_img/file/7033313933.pdfIn PDF document text
    • http://chi-kara.net/Upload/files/sowupojudujekabaz.pdfIn PDF document text
    • https://xtremefitness.com.au/application/third_party/ckfinder/userfiles/files/dejan.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=winning+eleven+english+ps1+isoPDF 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_off000178cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x178CC 10284 bytes
SHA-256: cabc48ef6cf3b5ca07f8dc7889d417fd22917f68ccab6fd24a8de711578ebc61
font_01_sfnt_off00018fda.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18FDA 20516 bytes
SHA-256: 2e253ce838574cc706224a71f290805a59fc35debd1dadbc6cd66b22c77daf48
font_02_sfnt_off0001c5c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1C5C8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1