Malicious PDF — malware analysis report

Static analysis result for SHA-256 12c8b12f547510cc…

MALICIOUS

PDF

73.2 KB Created: 2021-09-11 17:11:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 0c928defec6f125c030e5e3336df7638 SHA-1: 72d319d2781241cb7be64afbb7046f2c332f71b7 SHA-256: 12c8b12f547510cce03af9fddec61244772830965ab7d31de679c8757f82574c
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous embedded URLs pointing to compromised websites and other PDF files, suggesting it's part of a link farm designed to redirect users to malicious content. The presence of external URI heuristics and link farm detections strongly supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://smidgel.ru/uplcv?utm_term=how+many+pages+in+do+androids+dream+of+electric+sheep PDF link annotation
    • http://gruppocinofilomarsalese.com/userfiles/files/99481978713.pdfIn PDF document text
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/1f7837debdccdbe1df81ab9fa980af10/28188940977.pdfIn PDF document text
    • https://duext.com/wp-content/plugins/super-forms/uploads/php/files/398723c56433b17d62e35ca3e6cfde7e/91530997623.pdfIn PDF document text
    • http://willettelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/lazagafilumerobulizesi.pdfIn PDF document text
    • http://lesbambousbleus.fr/ckeditor/upload/files/nepalazifobipojoxeroguw.pdfIn PDF document text
    • http://autosoftware.company/autoresponders_images/files/27408240030.pdfIn PDF document text
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613254ced6dd7---wugureg.pdfIn PDF document text
    • http://royalgoodviewresort.com/Uploads/file/paboredo.pdfIn PDF document text
    • https://voicelux.ru/wp-content/plugins/super-forms/uploads/php/files/825c403f4d331d1ec0b2f3b298cff2a1/vudosubixozekalegif.pdfIn PDF document text
    • https://ce-mi.pl/uploads/userfiles/files/58872828974.pdfIn PDF document text
    • http://www.xpresswedding.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c8db1afe42---41491794844.pdfIn PDF document text
    • https://dudikom.pl/userfiles/file/83904162007.pdfIn PDF document text
    • https://hotel-la-licorne.fr/userfiles/file/muzudosiwu.pdfIn PDF document text
    • http://asbufestival.com/uploads/FCK_files/file/69725230699.pdfIn PDF document text
    • http://atomicattack.com/atomic/fckimages/file/89304915068.pdfIn PDF document text
    • http://www.valaisconsulting.ch/file/16226923693.pdfIn PDF document text
    • http://sirinthepgroup.com/userfiles/file/67074127264.pdfIn PDF document text
    • https://airxps.com/userfiles/files/62574827276.pdfIn PDF document text
    • http://xn--hy1bt45apoap01a.net/jangheung/userfiles/file/zibojizekinunil.pdfIn PDF document text
    • https://playgametoday.ru/wp-content/plugins/super-forms/uploads/php/files/311942834064682f1d396893d6d929a0/sakap.pdfIn PDF document text
    • http://sgyscom.com/upload_fck/file/2021-9-7/20210907003004766664.pdfIn PDF document text
    • https://macronew.com/upload/files/42184174791.pdfIn PDF document text
    • https://baoyi-chuck.com/ckfinder/userfiles/files/gofevir.pdfIn PDF document text
    • https://cashcruis.ru/wp-content/plugins/super-forms/uploads/php/files/3e2deeff3dd8669cee9822cb4a0347cc/zimeg.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_off0000bb10.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB10 11256 bytes
SHA-256: ef8826678d93b72dc91296a6b4def2556f397d546e79ea6bffd21e64064d37e7
font_01_sfnt_off0000d520.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD520 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ed32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED32 16276 bytes
SHA-256: 3691a6add7cebf18458627cf756bcc11303383f562f060575c94a3e22cfe5640