Malicious PDF — malware analysis report

Static analysis result for SHA-256 88ce7bfe307979ae…

MALICIOUS

PDF

71.9 KB Created: 2021-09-01 22:01:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 968ada24e79dcdf684a550958494e604 SHA-1: 8b2efd5bdaedeef020557bde498afa311a6f7901 SHA-256: 88ce7bfe307979ae9ec4b5befb5b55bc21dbb0bbefb18591c1eab3a0255c5160
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories, indicating a link farm designed to obscure the ultimate destination. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. The presence of multiple link farms on disposable or compromised hosting further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://nestaerospace.com/uploads/file/duxugozeregaguseseges.pdf In PDF document text
    • http://purpledoorchurch.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083e172adb1a---vebozokikekuwuva.pdfIn PDF document text
    • http://qkmedica.com/uploads/userfiles/file/31065452347.pdfIn PDF document text
    • http://heyumpnd.com/userfiles/file///jenugigupirekofobezutodi.pdfIn PDF document text
    • http://akkoryazilim.com/userfiles/file/setimumiwaterotovukura.pdfIn PDF document text
    • http://niezapominajkowo.eu/userfiles/file/sukixore.pdfIn PDF document text
    • https://empresa-venta.hr/files/beterobujinipixiwu.pdfIn PDF document text
    • http://gorisum.net/fckeditor/upload_file/file/gadazazojo.pdfIn PDF document text
    • https://3drm.bg/uploads/pictures/files/radezuwuzibezune.pdfIn PDF document text
    • http://cuacongtrinh.vn/upload/files/gojafososipuzofamanavib.pdfIn PDF document text
    • https://spa-salon.ru/ckfinder/userfiles/files/37080656907.pdfIn PDF document text
    • http://www.deco-interieure.com/userfiles/file/66778754565.pdfIn PDF document text
    • http://almawred-sy.com/files/adminfiles/files/rugapinorudoxadiriraset.pdfIn PDF document text
    • http://studiotecnicodama.it/userfiles/files/penir.pdfIn PDF document text
    • http://countrysquirefoods.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c3a74e15a2---bejakatujobozetomoka.pdfIn PDF document text
    • https://okazdedziecko.pl/_files/Media/file/komibim.pdfIn PDF document text
    • https://htchninc.com/d/files/41123268744.pdfIn PDF document text
    • https://grandplaza.bg/uploads/assets/file/kolimuwunojod.pdfIn PDF document text
    • http://naasschoolofmotoring.ie/fckeditor/userfiles/file/4470887086.pdfIn PDF document text
    • https://femagnet.com/upload/edu/article/file/varabiseni.pdfIn PDF document text
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cb22c93edc9---4518566401.pdfIn PDF document text
    • https://www.hotel-palladium.gr/wp-content/plugins/super-forms/uploads/php/files/v8c1na79fq8rojq8lmik51gcti/18666536402.pdfIn PDF document text
    • https://erdemlerkoleji.com/resimler/files/54341703299.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=lung+cancer+with+hypercalcemiaPDF 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_off0000b731.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB731 16692 bytes
SHA-256: fa24e28eeff438b3880688ccbc727a2be6d22ee3dd266e2a0c601c2811ded074
font_01_sfnt_off0000e1ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1AE 10792 bytes
SHA-256: 8543d48e4a54bfa49bccf9b342589c9d0f9e8f34fc811f39ee7c8ffecfbf2ce8
font_02_sfnt_off0000fa64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA64 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1