Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c5a81b45584df5c…

MALICIOUS

PDF

83.1 KB Created: 2021-06-27 10:31:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f48b4022764bad3a44880c1b35de40ba SHA-1: bb292ee4dd667ee9fecbcb024141adea82df68b0 SHA-256: 4c5a81b45584df5c811aa26b8ca2030b9e7dff706f9ed5cf5e7d465c2b932b95
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded links, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. Although no scripts were directly extracted, the heuristic firings and URL patterns are highly indicative of a malicious PDF designed to redirect users to harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://nomylo.ru/uplcv?utm_term=galatians+quiz+questions+and+answers
    • https://deltagroup.bg/uploads/file/4276273853.pdf
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1606f2085df4a9---59248631017.pdf
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7b55226ad5---64451365068.pdf
    • http://sochisushi.nl/survey/userfiles/files/zerukofovolejasagawunem.pdf
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160986a7c81c2a---zaxukokoruligidokomedepet.pdf
    • https://eyetracking.pl/userfiles/file/sevatomituxavumobibunuka.pdf
    • http://bycongroup.com/UserFiles/file/xizewolovujakepimodu.pdf
    • http://herodumpsterrental.com/wp-content/plugins/super-forms/uploads/php/files/b27754a5d1e67437ca0f344821f067d1/64037146175.pdf
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607a5b2a579c7---69134266320.pdf
    • http://labcoop-jsc.com/wp-content/plugins/super-forms/uploads/php/files/9ekhsot42crelt60rvra6s7e2u/gawekepilebefunagijazoran.pdf
    • http://kco.su/userfiles/file/87725515250.pdf
    • https://addsfly.com/userfiles/file/16058170469.pdf
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/r654dj9d159vjg0nd17pcen290/pagobiwosojejegasaxabumes.pdf
    • http://asalsold.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d4dbf36ea68---45541910019.pdf
    • http://pamat.ro/UserFiles/file/73494430725.pdf
    • http://arch-teh.com/pic/userfile/lirodakugizetabuwovep.pdf
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/4fa0e1334865fd42178d6e60910e2e46/30266516833.pdf
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e1a7d7d18d---sepasupulafetizoketirul.pdf
    • https://roweryelectra.eu/app/webroot/uploads/file/16198939688204.pdf
    • https://wkd-uk.com/wp-content/plugins/super-forms/uploads/php/files/b53ea65add5940a6eb1c005905d21a48/41130982073.pdf
    • https://brokenspoke.com/wp-content/plugins/super-forms/uploads/php/files/9878b1ef0f7c59fb55ea33b59403eb4d/titurabajesa.pdf
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/jkdgkok51tdcpcar66qsj3beel/31265492249.pdf
    • https://www.hauptsache.cc/wp-content/plugins/formcraft/file-upload/server/content/files/160ab31955ad1a---27965879625.pdf
    • http://mirrorgallery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091ae916fc22---saxoruzenelepaxadeki.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_off0000e4e6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE4E6 16792 bytes
font_01_sfnt_off0000fcfd.bin
51203849b41ba8fbbb5de1cbbfd328836b18cb76a861bd50d5a1c7fa4c6ca55f
pdf-font-stream PDF embedded font (sfnt) at offset 0xFCFD 10672 bytes
font_02_sfnt_off00011580.bin
4c0d97579adcb30313e0cc5b6c36cd5e5ec04bb060369a1517d956490fab346c
pdf-font-stream PDF embedded font (sfnt) at offset 0x11580 16172 bytes