Malicious PDF — malware analysis report

Static analysis result for SHA-256 855b07c0f7880f05…

MALICIOUS

PDF

78.1 KB Created: 2021-08-03 21:11:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: a72892d45fa84ed0e4e72115334e6725 SHA-1: 20c277bb753a9b3d07c1f45142bb2f0490793245 SHA-256: 855b07c0f7880f05a7080a39eb797e65011aaa1c8d9560a442f7d95876576797
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate the document contains a link farm pointing to compromised WordPress upload directories, suggesting an attempt to host malicious content or redirect users. The presence of numerous unknown URLs further supports this, indicating a likely phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://avtoarka.ru/wp-content/plugins/super-forms/uploads/php/files/c1b60d86287ff7e0d812bfa5c96b6952/8731753049.pdf In PDF document text
    • http://brothersaluminium.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/160d37ed578c5e---23136594796.pdfIn PDF document text
    • https://humble-brag.com/wp-content/plugins/super-forms/uploads/php/files/9a6el36s8bqsu1f4v7eumdplef/53793223259.pdfIn PDF document text
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16077e6e8df2ea---49889127685.pdfIn PDF document text
    • https://www.bakirkoytemsilcisi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079c2600cf8b---35615282276.pdfIn PDF document text
    • http://liavanhaeringen.nl/userfiles/files/xivadumorakexapila.pdfIn PDF document text
    • https://bowenpainter.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b008cfc7b39---gevofafivipopexigomizol.pdfIn PDF document text
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16098765b7bd39---95436031223.pdfIn PDF document text
    • https://carlojans.com/cms/file/pibevujuduloxo.pdfIn PDF document text
    • https://newat.ru/wp-content/plugins/super-forms/uploads/php/files/789349d9944859ac7985fab110803f80/10147236928.pdfIn PDF document text
    • https://broadstripe.com/wp-content/plugins/super-forms/uploads/php/files/a19b2f4dc13c88a9cccceaaf2295175a/80493138310.pdfIn PDF document text
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1675f82216---76845359524.pdfIn PDF document text
    • http://alacartedesign.de/userfiles/file/69613653224.pdfIn PDF document text
    • https://phoenixknights.co.uk/wp-content/plugins/super-forms/uploads/php/files/050a757ae0fe86a6807285b50f7b2572/70232256583.pdfIn PDF document text
    • https://nabijdefossa.nl/upload/files/forazowu.pdfIn PDF document text
    • http://3wsystems.com/shipinc/userfiles/files/belopapuvanozuguw.pdfIn PDF document text
    • https://jfefood.com/wp-content/plugins/super-forms/uploads/php/files/4f09c29563142bfa532931bd7aac61b2/nukiworunerifozetunebunas.pdfIn PDF document text
    • https://ikitellirezistans.com/upload/files/kogoliron.pdfIn PDF document text
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1609e32f66aad0---bebozogiduminixaxul.pdfIn PDF document text
    • https://zlato-eu.cz/upload/files/fopolidakipomev.pdfIn PDF document text
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a05d599068---bupapisefiwududofazuw.pdfIn PDF document text
    • http://hkalc.com/userfiles/17591930343.pdfIn PDF document text
    • http://hpworld.hu/data/pic/Image/file/tuxivujokigisufilemezoxa.pdfIn PDF document text
    • http://kinogigant.com/sadm_files/29250602633.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=telenovela+el+cuerpo+del+deseo+capitulo+32+completoPDF 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_off0000c9c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9C1 18036 bytes
SHA-256: d4b78c75b6d38d20327bea49cc7dca71aed10acce37031915326a5456cc066aa
font_01_sfnt_off0000f7f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7F3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001100a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1100A 11096 bytes
SHA-256: dc8a4ce2b53d023b50c1d62310bebd3eb55fe700e55c0c8067b431b8fed83009