Malicious PDF — malware analysis report

Static analysis result for SHA-256 37d812beb1936686…

MALICIOUS

PDF

77.0 KB Created: 2021-09-01 21:37:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 576fdcd7bc1ca081b83fae79a07fe40a SHA-1: 693ffc4ef2620794f3259d47870aed1e22434828 SHA-256: 37d812beb193668690cad5ac489f9684a32a678b30ae676be94e772dd925161e
156 Risk Score

Malware Insights

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

The sample was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It functions as a link farm, directing users to multiple URLs hosted on compromised WordPress sites. These links likely lead to phishing pages or further malware downloads, indicating a multi-stage attack. No scripts were extracted, and the document body was unreadable binary data.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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 http://basyapiemlak.com/yukleme_klasoru/userfiles/file/pibiwit.pdf
    • https://razdolle.by/wp-content/plugins/super-forms/uploads/php/files/21foei15mgvq280aqu59auk502/12410719760.pdf
    • https://masterok-kovka.ru/wp-content/plugins/super-forms/uploads/php/files/c61779d09e8dbeefda22bdb85a35469b/suxagebebo.pdf
    • https://stillwaiting.org/userfiles/file/tarofofodivuwinis.pdf
    • http://sahamit.net/userfiles/file/pesusuguve.pdf
    • http://flatadministration.com/uploades/fckeditorfile/vinotomosun.pdf
    • https://jetaime-shop.com/files/loperiloloxemasifonub.pdf
    • http://www.cheapmotorcycleinsurancepa.com/wp-content/plugins/super-forms/uploads/php/files/367bbhfe7qfjrpire0vvdtva84/tuvatisege.pdf
    • http://a-xian-coat.com/uploads//files/202108042105072169.pdf
    • https://myupfield.link/wp-content/plugins/super-forms/uploads/php/files/eeiuqgi3jv3t3iuopb5ats46og/domeniwipumi.pdf
    • http://apart1day.ru/file/67022774187.pdf
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/v1bbaltq1dng96v3aiij9pe91p/xopurumozirokorin.pdf
    • https://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608084351b38f---nekegojoxosusififiruk.pdf
    • https://bursakaynak.net/userfiles/file/mofoganosijotagefimojoz.pdf
    • https://abofahed.com/userfiles/file/mubukigutuxamisosaz.pdf
    • http://gallery4walls.com/upload/editer/file/81163758893.pdf
    • http://yngc.ru/admin/ckfinder/userfiles/files/64839541384.pdf
    • http://www.urbanwaterways.info/files/70276862454.pdf
    • http://a-swiss.com/upload/userfiles/file/vulis.pdf
    • http://homesunshinepharma.com/upload/files/likijufudimisudubu.pdf
    • http://jockmurray.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d86b287f8c---gijanizelifisagiwunimedi.pdf
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb910aa399d---38427224416.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=how+to+draw+flurry+heart
    • 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_off0000c530.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC530 16792 bytes
font_01_sfnt_off0000dd47.bin
c5d44f179d84bf24fe23d689444420d8f4de2c87712ca817eb744380cbf7300a
pdf-font-stream PDF embedded font (sfnt) at offset 0xDD47 10376 bytes
font_02_sfnt_off0000f4e8.bin
b3f17d9f1fcb9d29a1ea28472b7e4f25ae85d9bfc9b31d0caeee1a5f4c36698d
pdf-font-stream PDF embedded font (sfnt) at offset 0xF4E8 18676 bytes