Malicious PDF — malware analysis report

Static analysis result for SHA-256 82d44e69f452333b…

MALICIOUS

PDF

78.7 KB Created: 2021-09-23 20:24:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: a5ba1aa90677baab7779a1e2c5b05729 SHA-1: 410dd531102516078062b3fe6cb5118702a4a952 SHA-256: 82d44e69f452333bc6d76113261c101e24fe9e3a74287b8bb40d52e523bc7756
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external resources, many of which are hosted on disposable domains and appear to be part of a link farm designed to obscure the ultimate destination. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to trick users into downloading a secondary payload. The presence of embedded URLs and the PDF_RANDOM_URL_LINK heuristic further support this conclusion.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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
  • 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.
  • 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://cwesp.biz/upload/file/78767657382.pdf In PDF document text
    • http://dolphinegypt.net/userfiles/file/bitiwipe.pdfIn PDF document text
    • http://lucidareemantenerepavimentifaidate.it/userfiles/files/zufisel.pdfIn PDF document text
    • http://vonschickenconcord.com/uploads/files/79589622490.pdfIn PDF document text
    • http://itcbeautytrainingschool.com/userfiles/file/jejasotevizugedubonujabom.pdfIn PDF document text
    • http://aasghsflqsae.handylover.com/upload/files/keroguponupugenu.pdfIn PDF document text
    • http://conelser.hu/fck_uploads/file/debev.pdfIn PDF document text
    • http://benedictinoselrosal.org/ckfinder/userfiles/files/pagosebalisuga.pdfIn PDF document text
    • https://baxsporthorses.nl/userfiles/file/muwivaninegoviremugedefub.pdfIn PDF document text
    • http://cuacuonanbinh.com/userfiles/file/bogeruribexevupemuj.pdfIn PDF document text
    • https://olivermilk.vn/tctt/sites/aaa/file/pasapuziwevijowunozosotu.pdfIn PDF document text
    • https://bc2000.order-pro.com/ckfinder/userfiles/files/vipojexudeliguvalaxeme.pdfIn PDF document text
    • https://estoniapools.com/contents/files/89516602084.pdfIn PDF document text
    • http://idevicesplus.nl/app/webroot/files/userfiles/files/pujuraf.pdfIn PDF document text
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134fc23ae67b---winukidejavoxodajid.pdfIn PDF document text
    • https://n-vv.dk/userfiles/file/71150272652.pdfIn PDF document text
    • http://vin-baietii.ro/ckfinder/userfiles/files/36001437782.pdfIn PDF document text
    • http://www.jobsincrete.gr/images/_user_na/file/rolemapinidekenego.pdfIn PDF document text
    • https://speeddating.lt/speeddating/ckfinder/userfiles/files/rutepekesijenemuloxox.pdfIn PDF document text
    • https://thefencedocumentary.ca/adminfiles/file/nesarusujemirivutipu.pdfIn PDF document text
    • https://cfacgroup.com/uploads/FCK_files/file/niparonujozukodiwimam.pdfIn PDF document text
    • https://rockyhotelsgroup.com/uploaded/files/laboxizukulisazireme.pdfIn PDF document text
    • http://szyldkj.com/luodan/images/userfiles/file/53228079976.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=hill+climb+racing+hack+download+for+pcPDF 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_off0000cf26.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF26 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e73d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE73D 10976 bytes
SHA-256: ceaf7ba630217dd45f89ab12dc2123b0bdcfe0da4badd30efd35e630384be903
font_02_sfnt_off00010000.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10000 17432 bytes
SHA-256: 6608a5d2afdabe9d296e2682de67a8dd745e3579c82ab8957e0749f0ce7446e0