Malicious PDF — malware analysis report

Static analysis result for SHA-256 55f791d01c79891f…

MALICIOUS

PDF

110.2 KB Created: 2021-06-29 18:35:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: f4a445d7c7fde757be5586d7a303afa4 SHA-1: b09f3375a73d7d058a8f34b943bcddd4a2ee07f5 SHA-256: 55f791d01c79891f158ed4b83dff569a848397841e40e881e20ae30c5dd87b87
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it functions as a link farm. It contains numerous external URIs, many pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to lure users to malicious sites. The presence of embedded JavaScript further supports its role as a potential delivery mechanism for phishing or malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9698

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 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://cal.lighting/wp-content/plugins/super-forms/uploads/php/files/2d8c411b977762b2f391bd3fdbd91361/15249749394.pdf In PDF document text
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9945e820b---82693832080.pdfIn PDF document text
    • http://prosquash.by/data/1490081176.pdfIn PDF document text
    • http://akiyastyle.com/app/webroot/js/ckfinder/userfiles/files/judozapimewozaxufegikowob.pdfIn PDF document text
    • http://extracam.es/app/webroot/arxius/file/89353775444.pdfIn PDF document text
    • https://parokisantolukas.org/Uploads/userfiles/files/nibig.pdfIn PDF document text
    • https://sckprime.com/wp-content/plugins/super-forms/uploads/php/files/bf6f2c333360eaf1bd499627ec8624b8/zedevufu.pdfIn PDF document text
    • http://bamt.be/wp-content/plugins/formcraft/file-upload/server/content/files/160a01c3aceb53---wurenimoruretilawewo.pdfIn PDF document text
    • https://www.cr-sdc.org/wp-content/plugins/super-forms/uploads/php/files/a9215b9c01ba22e638a70f55db92d066/4980789377.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083645aa0ecd---gomukonelifemobaroviponek.pdfIn PDF document text
    • http://www.findvoters.com/userfiles/file/kokelugoba.pdfIn PDF document text
    • http://pvsystexperts.com/wp-content/plugins/super-forms/uploads/php/files/o5uvnfp1uarlj5n9mc6msp1j66/lugaxoxogozuwodunafive.pdfIn PDF document text
    • https://stakeoutllc.com/wp-content/plugins/super-forms/uploads/php/files/7f271977535f79ff85a9db6e7b5da2b3/11034204904.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/65ec4bef11e9a2cd64bffb0d6fe2883c/mawokaretamepodoxemoxub.pdfIn PDF document text
    • https://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c26ec861ecf---8810928961.pdfIn PDF document text
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160bf9ed9db222---1454769753.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/b423f763697d3f991fb433cbfee7b5c7/93270312462.pdfIn PDF document text
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac1b1a83030---9393434498.pdfIn PDF document text
    • http://raisemoneyonline.org/clients/6/69/691275cf9a36cab982b2498ebdc715be/File/67244493039.pdfIn PDF document text
    • https://www.toptalentusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aad681b7b32---zegarilikal.pdfIn PDF document text
    • http://alumcity.ru/userfiles/file/63590721949.pdfIn PDF document text
    • http://cw-cut.com/uploads/file/danoki.pdfIn PDF document text
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/160af818c48b1c---mawinupon.pdfIn PDF document text
    • https://www.chartsunlimited.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/1608aa342d7a6c---43110635044.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=amino+aesthetic+blog+templatePDF 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 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000107d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107D5 10840 bytes
SHA-256: d27132dda3c10cacbe47bdfc649a2a05229fbc944074c1fa1dfa31840b6efe42
font_01_sfnt_off0001206a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1206A 2040 bytes
SHA-256: 7d0a022c21dfbd31b44052fc40a1a017ff132cf5aaace532726983399c694ce9
font_02_sfnt_off000129d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129D4 29140 bytes
SHA-256: 7236c117e3cce0adf7f64b2a3044c977515a6009e033192aab4ec9f585410683
font_03_sfnt_off000170e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x170E6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_04_sfnt_off000188f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x188F7 19872 bytes
SHA-256: edd7aed1a6fb7d9673a26615796a9a1605fe84e1e65b36ba6b5e900387f72164