Malicious PDF — malware analysis report

Static analysis result for SHA-256 37f4ce66536ebbf8…

MALICIOUS

PDF

70.0 KB Created: 2021-09-06 12:54:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3b2b476257650322868d63b04fd67a66 SHA-1: 631f01f0c37ec418b5c3cfbef4f494d14d4c6f42 SHA-256: 37f4ce66536ebbf8a1fc9a1898e14bde34a797a05f5a94ad9c98f65d25beac6f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a link farm pointing to multiple compromised WordPress sites, which in turn host other PDF files. This structure suggests a phishing or malware distribution campaign where the initial PDF serves as a lure to download further malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609adb5095712---kitirovude.pdf
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/b175784f04419c8939e2bf16f2096530/repenozefefitovovisapo.pdf
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a26567dcf9b---dafakorib.pdf
    • http://ettermanenterprises.com/ckfinder/userfiles/files/fijeteri.pdf
    • http://gestmase.com/media/images/file/55393465244.pdf
    • https://presentkompaniet.com/img/content/file/3001485153.pdf
    • https://www.die-umzugsfabrik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d6863d35992---9697133879.pdf
    • http://ranaghatpchsschool.org/userfiles/file/19826292872.pdf
    • http://vytvarnyobchod.cz/UserFiles/File/75971974635.pdf
    • https://interesttour.com/wp-content/plugins/super-forms/uploads/php/files/52f3aa29158bc8f09cd9fa85fa43171d/wogex.pdf
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bf8e31a2cbf---13853833983.pdf
    • https://annjulieskarpmo.com/userfiles/file/63793285556.pdf
    • http://kimsanghun.com/upload/userfiles/file/2021812113543568.pdf
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/32961f66b66760352b4de43aa0931527/9925736001.pdf
    • https://www.certificagreen.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077c9d10cf5a---37305549204.pdf
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/tgkllmhdaqfv7vifgsrtf194a2/gokoremutejamemumofabi.pdf
    • http://firmykominkowe.pl/Obrazki/edytor/file/99458749141.pdf
    • http://mdsalon.ru/img/lib/file/rorijefuvelapuxobepitus.pdf
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/1606e5a30296b6---97828846048.pdf
    • http://theofficefurniturestore.com/ckfinder/userfiles/files/63034539667.pdf
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131f5c61b39b---50240932982.pdf
    • http://nhuaduongnhapkhauaz.com/upload/files/68649123195.pdf
    • https://www.edmcenter.xyz/ckfinder/userfiles/files/fulokif.pdf
    • http://vanprodukt.cz/UserFiles/File/29751847466.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=vlsi+text+book+pdf
    • 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_off0000b309.bin
ea6d19b98ef2518b76533031e26c3e7e0c2ae4f4f7fd90fda6056b955a840b4a
pdf-font-stream PDF embedded font (sfnt) at offset 0xB309 15644 bytes
font_01_sfnt_off0000db4a.bin
6fc6aeb16ec73487a9b4dfe68e9fda8af34f0f9c06bf490f3f8de060a2d9f47a
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB4A 10428 bytes
font_02_sfnt_off0000f2da.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF2DA 16792 bytes