Malicious PDF — malware analysis report

Static analysis result for SHA-256 16c5887998bbcbb6…

MALICIOUS

PDF

83.4 KB Created: 2021-09-07 17:10:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3a705a51c1a7abf7c34d668c2a3eecaf SHA-1: c112b0bf3cbfc43bf0fb5024f087ef2f84e64321 SHA-256: 16c5887998bbcbb60404b7b80e51e2750999bfb38dae3ed66bd830fff7c8da58
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan payload. It contains numerous embedded URLs, many pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of these links and the overall structure strongly indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://studioingegneriavaragnolo.com/userfiles/files/61607560843.pdf
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/4p1ic7qsun3lc70pad3uv1la84/94077032323.pdf
    • https://socohoteldanang.com/uploads/image/files/2804013817.pdf
    • https://uzmanwebci.com/calisma2/files/uploads/13820100481.pdf
    • https://aeap.com.br/ckfinder/userfiles/files/kinaradufitugitopaxere.pdf
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/92d043c7af449166a8931e4556de5f1f/jutomepidufa.pdf
    • http://www.esthemed.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160c97ba56c01b---78509011209.pdf
    • http://beckydavidsonhomes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2bdc77250d---kelatugokobeloz.pdf
    • http://vstarmp.cn/upload/files/20210619_085347.pdf
    • http://hypotekaprezamestnancov.sk/res/file/jesamikup.pdf
    • https://network-italia.com/file/39394893987.pdf
    • http://greenbrier101.com/userimages/tejaxawiveluxisex.pdf
    • https://primeodontorj.com/wp-content/plugins/super-forms/uploads/php/files/6b3e5eb7199614a6cc4e944a19a96582/28033046960.pdf
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/160bab2219e42f---147568615.pdf
    • http://masterref.ru/editorfiles/file/78448647147.pdf
    • https://www.finestkindcharter.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f39db216ab---zazoximelo.pdf
    • http://csc020.com/userfiles/file/20210731164500_uc6us0.pdf
    • http://bosch-elektronarzedzia.pl/catalog/file/tuwalonekoxevigifozef.pdf
    • https://gservicepz.com/wp-content/plugins/super-forms/uploads/php/files/fca2e980d3df357bc8f74640a55d8bbf/bipegera.pdf
    • https://www.fifatravels.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608bd16c7b455---45216103998.pdf
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/161359ce259756---3150361390.pdf
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2cf3c5b565---rinamod.pdf
    • http://soflocops.net/clients/81266/File/88697684669.pdf
    • http://hillcountryawningsandsunscreens.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608622b54bbd3---vepolabib.pdf
    • http://hainescentreasia.com/images/file/zijiloge.pdf
    • https://www.proctoloji.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b9ff7ced51---fiduvawinuburelukofon.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=taylor+marshall+infiltration+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_off0000e2da.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE2DA 16792 bytes
font_01_sfnt_off0000faec.bin
2c9913dd417aa1de94a78823b5871e0b17ddb74637fa8b06d21923783ea94212
pdf-font-stream PDF embedded font (sfnt) at offset 0xFAEC 17180 bytes
font_02_sfnt_off00012703.bin
e62ddc1707d7d9c4e39fa164816f53ede7ea01889c0536505be2ac542eaaad5d
pdf-font-stream PDF embedded font (sfnt) at offset 0x12703 10708 bytes