Malicious PDF — malware analysis report

Static analysis result for SHA-256 031f1f8b61913132…

MALICIOUS

PDF

83.6 KB Created: 2021-06-30 01:56:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: ec254e38b07b267cd03bed91d0157419 SHA-1: 28c0225c317df4517876d15ef6b1469c05dd1680 SHA-256: 031f1f8b6191313245100fd5961afc6c2744d4c1d775b7b3c0e3ba34fe2f5cd2
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous URLs pointing to compromised WordPress sites, suggesting a tactic to distribute malicious content or engage in SEO spam. The presence of multiple distinct hosts and the use of UTM parameters in some URLs further support this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

Heuristics 6

  • 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.
  • 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://catamma.ru/uplcv?utm_term=impressionism+and+expressionism+music PDF link annotation
    • http://grani-tonkogo-mira.ru/wp-content/plugins/super-forms/uploads/php/files/aae64d1cf2376c6672268271fa48205f/35044060501.pdfIn PDF document text
    • https://stpetejazz.com/wp-content/plugins/super-forms/uploads/php/files/875kljrsg44tt2gegubvop9dfr/dofowopudosikuximuwaxep.pdfIn PDF document text
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/67694f44173c491e91abf06bc5322418/8436645377.pdfIn PDF document text
    • https://alajuusa.ee/media/contents/file/lajiwojaremekutumanarojup.pdfIn PDF document text
    • http://christopherdallo.com/file/jejukurebiziziwufabid.pdfIn PDF document text
    • https://europartner2.pl/uploads/50080970844.pdfIn PDF document text
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a631d38041---87257811838.pdfIn PDF document text
    • https://sce.tw/uploads/files/60bfd6757b5cc.pdfIn PDF document text
    • http://elite-nails.pl/Upload/file/kewazim.pdfIn PDF document text
    • http://asude.istanbul/ck_images/files/kopotepufemine.pdfIn PDF document text
    • https://twr1115.net/files/fckeditor/file/9587997814.pdfIn PDF document text
    • https://messianic.live/wp-content/plugins/super-forms/uploads/php/files/52514464fc7d6b678b5fa07fbbfb688a/rodiviwegogurorelot.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/8a45bcb078b76f29e00b1c41fe01547b/52749891215.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ed4a04f9e7---repezubidurewokimerapukel.pdfIn PDF document text
    • http://asianmosaicnyc.com/userfiles/file/85683814049.pdfIn PDF document text
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606eed5d3cd09---biboreladivawe.pdfIn PDF document text
    • http://mg001.cn/upload_fck/file/2021-6-18/20210618174125104397.pdfIn PDF document text
    • https://www.pfgpartners.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16071c18ec0f90---2697348371.pdfIn PDF document text
    • https://amalighting.com/wp-content/plugins/super-forms/uploads/php/files/1f9594bd09e1e747015c57206d597e0a/pefivurumipikatobukobo.pdfIn PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/16095f503cb16d---97686031970.pdfIn PDF document text
    • https://gw21.ch/uploads/userfiles/file/10373585893.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607531ddb6278---23422493407.pdfIn PDF document text
    • https://alphacleanwashing.com/wp-content/plugins/super-forms/uploads/php/files/185990422484158de38d4b8e2323fc10/puvijamofuwisa.pdfIn PDF document text
    • https://bititechnika.com/uploads/file/fokufexoriwuxeverotibu.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/hgt5p4cjh4b3r3tfk65aofp7c7/wobimajunoriv.pdfIn PDF document text
    • http://dirabrealtors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a200f1c65b0---todojedizupomotifamuju.pdfIn PDF document text
    • 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_off0000e433.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE433 10684 bytes
SHA-256: 7df0de9be6ca79979a833ab87a71e8020c7ae277194b66991d116a2be1175b25
font_01_sfnt_off0000fc9d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC9D 17056 bytes
SHA-256: a5f4d3d57da832a1e93c119333eb4cc13622d1abc71cf9fb4e18af8eb1753484
font_02_sfnt_off0001289c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1289C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1