Malicious PDF — malware analysis report

Static analysis result for SHA-256 16e4a1e3445cae25…

MALICIOUS

PDF

79.9 KB Created: 2021-06-29 20:44:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f9137ef7554800e2ad6b8f0c0af27217 SHA-1: 7f68fbbc47c3c14e7c0c0c673311f834a437b9bb SHA-256: 16e4a1e3445cae25f04120971526f3fbcae03d3c04fb4b4885abe26234b2954b
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. It functions as a link farm, directing users to numerous compromised websites and potentially disposable hosting, suggesting a phishing or malware distribution scheme. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, further obscuring its true purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/c5bd8b7ec3a13f188a63772c9bbba0b2/80255109677.pdf
    • https://www.heracles-hotel.eu/wp-content/plugins/super-forms/uploads/php/files/eucc9rk8b9do7hgrfsgr47gr38/mezibixoxofilefave.pdf
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa0b4152e9e---32177423613.pdf
    • http://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c3dd32abce---1294144871.pdf
    • https://masterok-kovka.ru/wp-content/plugins/super-forms/uploads/php/files/1f07e59657073926873f93e234793dfa/patevizulovadupog.pdf
    • http://rolmech-strzelno.pl/Upload/file/49398173843.pdf
    • https://semineebrasov.ro/printuri-fi/files/zazimu.pdf
    • https://mobilieroccasion.fr/uploads/file/dajowuzamerusubezipoxopid.pdf
    • http://thaihotelsale.com/FileData/ckfinder/files/20210623_16D1A62092594D31.pdf
    • http://aihyang.com/userfiles/file/jixaka.pdf
    • http://www.kzhep.in.ua/wp-content/plugins/super-forms/uploads/php/files/7v9cj7ga974c7tdtvltb6gsom4/19282767850.pdf
    • http://anhuifan.com/upload_fck/file/2021-4-30/20210430142841541441.pdf
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607662bc9c282---93316784181.pdf
    • https://universal4shipping.net/userfiles/file/91604928489.pdf
    • http://marinapogon.pl/upload/file/69256661105.pdf
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160bc59b5993ef---40603176215.pdf
    • https://www.apollopowersystems.com/wp-content/plugins/super-forms/uploads/php/files/20022bb3ea89dd4812d8e050437d66ba/bijozogova.pdf
    • https://akproauto.com/nbloom/fckuploads/file/taselirudeseleranakab.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d2226ec7a5f---vunosoluvo.pdf
    • https://webtraffic.ch/wp-content/plugins/super-forms/uploads/php/files/nps6ojmrtdbo909djfctegkfk4/56079647686.pdf
    • https://studiogreenwich.ru/wp-content/plugins/super-forms/uploads/php/files/b790720b8630c5d0aad9e47f73264f5f/kuzuvimikokolojiz.pdf
    • http://www.advancedevents.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160c7885a8c706---98062560243.pdf
    • http://yjccnc.com/upload/files/levutefuron.pdf
    • http://planbmedia.hu/files/47152647919.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=oxford+new+pathways+class+3+solutions
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d34b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD34B 16792 bytes
font_01_sfnt_off0000eb62.bin
37f606166ae5d6749eba9e56808aa5715e2b2380e2215d7853dbe98f73c8a9ec
pdf-font-stream PDF embedded font (sfnt) at offset 0xEB62 11316 bytes
font_02_sfnt_off0001060e.bin
ee7ee085184d546a6c98e7b83391dcc06bcba044ed0b38b91296b5c309b65ccd
pdf-font-stream PDF embedded font (sfnt) at offset 0x1060E 17032 bytes