Malicious PDF — malware analysis report

Static analysis result for SHA-256 06f138b71ff2b577…

MALICIOUS

PDF

82.6 KB Created: 2021-09-06 02:16:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1b0f244e2c879c24544ce0cae5d4fca7 SHA-1: b41d16ce592365012a52c0d8fabce4b94f997781 SHA-256: 06f138b71ff2b57781a8451442fd1fe73388cb63ce970dac1c2e90d488b2271c
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many hosted on compromised WordPress sites or disposable domains, suggesting a link farm for phishing or malware distribution. The ClamAV detection and ML classifier strongly indicate malicious intent. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, but the presence of external links and the overall heuristic firings point to a malicious PDF designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://chcial.ru/uplcv?utm_term=2006+dodge+charger+service+manual+pdf
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/160c251a32dff9---65352589148.pdf
    • http://aan.kz/ckfinder/userfiles/files/lupetaxatugozokus.pdf
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bcc919cf9c5---14231342358.pdf
    • https://singaporeroadshow.com/wp-content/plugins/super-forms/uploads/php/files/b2228479d9d2b30e0815c132ab3e160b/jorogimalaxebotomi.pdf
    • http://placc.info/up_image/96444928365.pdf
    • https://southtours.com/wp-content/plugins/super-forms/uploads/php/files/9eglstdtdm6grobrbf54cgq0ob/gijaniwononegeji.pdf
    • https://navliecky.net/userfiles/file/35723310191.pdf
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a6615993179---5552067934.pdf
    • http://ambulatorioveterinariovianello.eu/userfiles/files/20681621205.pdf
    • https://www.hagensmarketing.com/wp-content/plugins/formcraft/file-upload/server/content/files/16097f7745281b---87526618726.pdf
    • http://bibrka-school.org.ua/ckfinder/userfiles/files/tozasazakasakofaz.pdf
    • https://mosoptagro.ru/wp-content/plugins/super-forms/uploads/php/files/760e82e070a919921855a7a89e0b2319/dukovixadefuvotajifib.pdf
    • https://chocoinmobiliario.com/wp-content/plugins/super-forms/uploads/php/files/c009d0b82338a07c83063f21533a5bb4/46358609588.pdf
    • http://olimpic.hu/ckfinder/userfiles/files/xizomixosiwagilexe.pdf
    • http://doubletroubels.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075315ed900c---vujawawavudufezexuze.pdf
    • https://mavismanagement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607cbf739c30f---13340872326.pdf
    • http://bioaec.com/userfiles/files/97452863987.pdf
    • http://cetinelektrik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160a60c300a70a---21670991620.pdf
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/ed900c42a7daa425c1a3e34fd9fc6fc0/69835307711.pdf
    • http://pizzeria-millemiglia.de/app/webroot/img/editor/file/20106523098.pdf
    • https://mpksieradz.pl/upload/file/fowuzadeleditas.pdf
    • http://execdentalclinic.com/uploads/ckfinder/userfiles/files/39905569095.pdf
    • http://www.ocptecnology.com/admin/uploaded/fck/file/88262281709.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_off0000ddfb.bin
2b61e4b1abbbc34b68cdbf9f7b8e9857d779a3e47d810e87af119cf788091749
pdf-font-stream PDF embedded font (sfnt) at offset 0xDDFB 16956 bytes
font_01_sfnt_off00010a59.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10A59 16792 bytes
font_02_sfnt_off00012270.bin
4fb218d391a4b6e2fa831854af32c2e1de84b806c81e8f5a5550da5dfbc8259d
pdf-font-stream PDF embedded font (sfnt) at offset 0x12270 11448 bytes