Malicious PDF — malware analysis report

Static analysis result for SHA-256 b3c4b3cdfe9da607…

MALICIOUS

PDF

80.1 KB Created: 2021-08-15 06:59:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e16e86e9a0d50e69fab71ef16a983f86 SHA-1: 7be3befd48fea345be558b5bc820562648a37043 SHA-256: b3c4b3cdfe9da6074d9942095bbe3b8b7aa8920dfb1311df71d26cc257524b8e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, indicating a phishing or malware distribution attempt. The heuristics reveal it functions as a link farm, directing users to numerous external URLs hosted on compromised or disposable domains. While no scripts were explicitly extracted, the nature of link farms in PDFs often involves JavaScript to facilitate redirection, suggesting an attempt to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://laborke.ru/uplcv?utm_term=cramer+84+studies+para+piano+pdf
    • https://senzedigicraft.com/wp-content/plugins/super-forms/uploads/php/files/a92b97fb730548cdbc2279bf39614582/jumemaraxul.pdf
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bbea22f14ae---rekuxu.pdf
    • https://fruzsiflame.hu/userfiles/file/10679734942.pdf
    • http://rgn2u.com/userfiles/files/rajosojonisom.pdf
    • https://cambodiadriverservice.com/userfiles/file/92157886501.pdf
    • http://suarezbeltran.com/aym_images/files/netowufepapetagekabofa.pdf
    • http://fusiongrup.ro/userfiles/file/53377064894.pdf
    • http://www.farparts.cl/wp-content/plugins/formcraft/file-upload/server/content/files/16087c182cbfb0---wekenirabodenodavazoxe.pdf
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/b8948df8cf7609ae047143c57dcf3578/fevokodulekexozeku.pdf
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16091536f73319---penesuwovuvikud.pdf
    • http://www.drivingschool-brno.cz/files/files/degebonopiwifokiji.pdf
    • http://self119.net/upload/userfiles/2021/07/files/210724185533.pdf
    • http://www.danvillern.com/wp-content/plugins/super-forms/uploads/php/files/6o9m2drg8eerqnpgrd0bdjg0b0/34965885967.pdf
    • http://www.darvidproperty.com/news/file/71419682410.pdf
    • http://greenbiotech.vn/uploads/userfiles/file/nefuronegatijesega.pdf
    • http://futurepoolandspa.com/ckfinder/userfiles/files/63210113421.pdf
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/161083102cd6f4---wubozevefaluvivata.pdf
    • http://incomsistema.ru/ckfinder/userfiles/files/12628832537.pdf
    • https://hideab.se/tc/Mediagalleri/file/jadigukit.pdf
    • http://mlkscholarshipsmilwaukee.org/clients/f/f0/f021f13c5c598389be7e913a1ae626ff/File/miputodiruluragodowa.pdf
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608d75bf3e828---zikuv.pdf
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609dd79ee1739---domonojiboromo.pdf
    • http://bio86.fr/fichiers/78171720450.pdf
    • http://superfasttv.com/uploads/files/poriranuwezisexu.pdf
    • http://kirilmazbardak.com/userfiles/file/vizixemepixibasofipedir.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_off0000ce57.bin
bb7251a5dd1d61be2c938b84f81f11a07904c992ea0d8935b853b622db1228bc
pdf-font-stream PDF embedded font (sfnt) at offset 0xCE57 11032 bytes
font_01_sfnt_off0000e808.bin
0eecf5860ae769177ffa6d0ac8d6584d6b3337cf481bfca06cc5fd502df9510e
pdf-font-stream PDF embedded font (sfnt) at offset 0xE808 19148 bytes
font_02_sfnt_off000118be.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x118BE 16792 bytes