Malicious PDF — malware analysis report

Static analysis result for SHA-256 b155b54173fe0e8c…

MALICIOUS

PDF

91.0 KB Created: 2021-09-14 13:36:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 1e41857b6bae6f3bb2244fdb7afaa946 SHA-1: 34624876332fb444bd265f8138882083494d9d2f SHA-256: b155b54173fe0e8ca6d8d268db0cdd7d12b361ca1fb85f0ca5686f0fdc2e7427
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. It contains numerous external URIs and link farm structures pointing to various domains, suggesting an attempt to lure users to external sites. The presence of a 'download button' heuristic further supports a lure-based attack pattern, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://elai.kz/upload/2021/09files/210904190145632162h105i.pdf In PDF document text
    • http://www.dkmodels.net/ckfinder/userfiles/files/28518494593.pdfIn PDF document text
    • https://onhimalayas.com/ckfinder/userfiles/files/61135720141.pdfIn PDF document text
    • http://titadoorbinhduong.com/upload/files/98476906575.pdfIn PDF document text
    • https://butagallery.com/userfiles/files/satotekemupipep.pdfIn PDF document text
    • https://urbanlivin.lu/userfiles/files/45257796940.pdfIn PDF document text
    • http://geofer.eu/userfiles/files/76590757559.pdfIn PDF document text
    • http://poketomecam.com/uploads/files/bolusediwuredizavus.pdfIn PDF document text
    • https://eclipsetheaters.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613032983f5b6---20518038702.pdfIn PDF document text
    • https://brigitte-farner.ch/userfiles/files/53955182594.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613960431a4b0---33041560058.pdfIn PDF document text
    • https://safarekhoob.ir/basefile/safarekhoobir/files/50918749199.pdfIn PDF document text
    • https://neoville.ru/wp-content/plugins/super-forms/uploads/php/files/319affbf122ba59abeb75353e1c52bd7/tojamobirepa.pdfIn PDF document text
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613375fb57e4d---sigelopurukivorobadaxewa.pdfIn PDF document text
    • https://xtrafitcoaching.com/www/images/files/42725383698.pdfIn PDF document text
    • http://klhl.com/userfiles/file/fenudujumamonogixeduvorum.pdfIn PDF document text
    • http://dobre-jaja.com/Upload/file/59013807606.pdfIn PDF document text
    • https://heuresromantiques.com/upload/files/jumufaxala.pdfIn PDF document text
    • https://igescanada.com/ckfinder/userfiles/files/96201187454.pdfIn PDF document text
    • http://laarakkers.com/ckfinder/userfiles/files/7648726824.pdfIn PDF document text
    • http://qianxish.com/ckfind_image/files/tirawonijefokaguje.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f2d26086a6---niwizefeku.pdfIn PDF document text
    • https://shibbirs.com/media/files/66028903924.pdfIn PDF document text
    • http://gdlejia.com/uploadfile/files/20210909_010446.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=gangstar+vegas+unlimited+money+modPDF 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_off0000f086.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF086 22956 bytes
SHA-256: 850e6eb4684112626421095a298fd777ef5a777a19397e3bbabf0668b347a286
font_01_sfnt_off00012d59.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D59 10912 bytes
SHA-256: 3b920fa73015e5be2f20a5bd7dee1d1275f94c14d2899c8da9004c4c26f6cbd4
font_02_sfnt_off00014676.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14676 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1