Malicious PDF — malware analysis report

Static analysis result for SHA-256 51b00be35de8167e…

MALICIOUS

PDF

85.1 KB Created: 2021-09-16 21:00:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: b62700aa00d35cf132d6b2cdfc46b1a4 SHA-1: 568d65179629e297c2dd9ba17295b85e9917fcc1 SHA-256: 51b00be35de8167efdb738d0a48f166f7636672f677f879d38500cc009224f1a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to compromised CMS uploads and disposable hosting, indicative of a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. No scripts were extracted, but the structure and URL patterns are common for malicious PDF lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://synerhu.ru/uplcv?utm_term=triangle+face+shape+hairstyles PDF link annotation
    • https://archcosmeticstudio.com.au/wp-content/plugins/super-forms/uploads/php/files/90565db96335992c50c01c3884308e0c/27789802152.pdfIn PDF document text
    • https://rwd1.thadv.com/upload/files/98665962392.pdfIn PDF document text
    • https://siliconautomation.com/userfiles/file/74155636198.pdfIn PDF document text
    • https://baoyi-chuck.com/ckfinder/userfiles/files/nepomizubotefesidofu.pdfIn PDF document text
    • http://aeusjtu.pretty-match.com/upload/files/nananetejaruvigib.pdfIn PDF document text
    • https://nibrasimansch.com/userfiles/files/96243823253.pdfIn PDF document text
    • https://oneremote.ru/wp-content/plugins/super-forms/uploads/php/files/4973beaffcfd5c80b81a72746043905c/kozokufutegesapajakunap.pdfIn PDF document text
    • http://shangrilatheshow.com/ckfinder/userfiles/files/vemowolavimawiradasedoja.pdfIn PDF document text
    • https://armature.ir/cache/fck_files/file/15278355433.pdfIn PDF document text
    • http://sweed-trans.eu/ckfinder/userfiles/files/jodidurubenagejupog.pdfIn PDF document text
    • http://www.homefacelifters.com/wp-content/plugins/super-forms/uploads/php/files/f63ddc5df26a6f610808fc147fe16ce6/79406968186.pdfIn PDF document text
    • http://gocreate.termall.pl/upload/fck/file/zofoxopa.pdfIn PDF document text
    • http://stmarysharipad.com/userfiles/file/pijimegejomawadi.pdfIn PDF document text
    • http://good163.cn/Uploadfiles/files/36841907526.pdfIn PDF document text
    • https://cradlegold.com/wp-content/plugins/super-forms/uploads/php/files/remknac6n0atf8bt4mv3t8ubre/53252004573.pdfIn PDF document text
    • http://say-international.eu/userfiles/file/70365906018.pdfIn PDF document text
    • http://balmybnb.com/t/tutorfirm/uploads/ck/files/fetadoxum.pdfIn PDF document text
    • http://svadbavmoskve.com/content/xuploadimages/file/50019003487.pdfIn PDF document text
    • http://doingthing.com/downloads/blog/geust/files/ritujerenefifakejo.pdfIn PDF document text
    • http://stickerbarcode.com/file_media/file_image/file/vafebizeveruwenet.pdfIn PDF document text
    • http://chukguwang.com/files/fckeditor/file/rebebagarunezut.pdfIn PDF document text
    • http://moneymaker-gold.de/files/xapunir.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_off0000e867.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE867 17816 bytes
SHA-256: 40ea2691069c25d30b1846cb1cfdcb4e8fd13ed4cbed17f474634195c5e5d5e0
font_01_sfnt_off000116a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116A7 10716 bytes
SHA-256: 4571137afee713673ef874fef50fb286dd2e93cf76f4784a037ff1953ca71ae6
font_02_sfnt_off00012f35.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F35 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1