Malicious PDF — malware analysis report

Static analysis result for SHA-256 87b9d73e58d23a08…

MALICIOUS

PDF

88.1 KB Created: 2021-08-17 22:06:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 8fae0cda06f689adda6fd79091a4e82f SHA-1: a5b537ca4cc7de4ea055e03220e27d0b583b387a SHA-256: 87b9d73e58d23a08f80fd0b04d7fdec46718f2dc0ba9b0c80574c0d861bf49aa
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal that the document contains a link farm pointing to compromised WordPress sites, likely serving as a lure to download further malicious content. The presence of multiple PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM firings supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://makaifruits.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f8e01f489b0---givibiwisuzeja.pdf In PDF document text
    • http://104.156.58.56/~web2inbox/wp-content/plugins/formcraft/file-upload/server/content/files/16098369e1a320---jatodutavam.pdfPDF link annotation
    • http://icwest78.com/clients/67591/File/25803424727.pdfIn PDF document text
    • http://thetachikappasigmaalumni.org/clients/5/56/56ac51e2ee760b54d3ff8b7d53c877b7/File/21563442988.pdfIn PDF document text
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f5d03c6901---85684114924.pdfIn PDF document text
    • http://burrburroughsfamily.com/clients/55468/File/fejawubifekorepelivewuj.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/16100d249ca9ee---62564615646.pdfIn PDF document text
    • https://www.emma-solutions.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609fdf548be0a---bezefonunolo.pdfIn PDF document text
    • http://xn--80aafbkbafwdti1ahihccrg.xn--p1ai/pict/file/15483527276.pdfIn PDF document text
    • https://resicolor.com/upload/files/zigewegosufewise.pdfIn PDF document text
    • https://gamletaarnhuset.no/wp-content/plugins/formcraft/file-upload/server/content/files/1607b855751cbb---83617085555.pdfIn PDF document text
    • https://giolog.biz/images/bulk_images/files/18248915272.pdfIn PDF document text
    • https://rivaflo-south.in/userfiles/files/watorusifotuk.pdfIn PDF document text
    • http://myblindz.com/fck_user_files/file/35301344686.pdfIn PDF document text
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b61a431fb2d---piwopulepuwu.pdfIn PDF document text
    • http://theopenhouseclub.com/wp-content/plugins/super-forms/uploads/php/files/ae70d281f93ef065fbf4aaf098aad05c/vogebaf.pdfIn PDF document text
    • http://bocghedanang.com/media/ftp/file/86205234492.pdfIn PDF document text
    • https://askopenko.com/wp-content/plugins/super-forms/uploads/php/files/de823239044d6557f840f80e3083a903/bimajuxibebulen.pdfIn PDF document text
    • https://mavachhaiphong.com/upload/files/rusizuwugukogij.pdfIn PDF document text
    • http://asiavent.com/UserFiles/file///xufazukifoto.pdfIn PDF document text
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607b063e36717---tosibuxawetitot.pdfIn PDF document text
    • http://kawoka.com/userfiles/file/dufazetoxukasovetijura.pdfIn PDF document text
    • http://www.skup.it/wp-content/plugins/formcraft/file-upload/server/content/files/1608aa7f53b1ad---62863339240.pdfIn PDF document text
    • http://benthanhsgfarm.com/images/uploads/files/fexiko.pdfIn PDF document text
    • https://www.electriclighting.com/wp-content/plugins/super-forms/uploads/php/files/f6c2322f6cc162620630579bf1debaa1/falevodexufi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=how+to+insert+multiple+page+pdf+into+word+macPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f31d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF31D 17516 bytes
SHA-256: b74defc1a320246af8fb33a3ecd885bafbcd1c306600e57cd6ee0ff8fac0a18c
font_01_sfnt_off00012101.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12101 11140 bytes
SHA-256: e510f9772bf4519a8306e8aaa069c727edf80cf06cc2c34cdc51280c1e5377ad
font_02_sfnt_off00013ad9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13AD9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1