Malicious PDF — malware analysis report

Static analysis result for SHA-256 aeac5b44fa6e061c…

MALICIOUS

PDF

68.4 KB Created: 2021-09-10 07:23:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 99ca4f8e33ade719633882e44fdafc55 SHA-1: ad0d8904c6b000b811aa44246423b20c70780bb5 SHA-256: aeac5b44fa6e061cd8b1cc300e08a0565da615d1abc9ff5530744985d6e6307d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous URLs pointing to potentially compromised websites or disposable hosting, suggesting a phishing or malware distribution scheme. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of techniques used to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://laborke.ru/uplcv?utm_term=worksheet+of+adjectives+for+class+2 PDF link annotation
    • http://guowangcable.com/d/files/kuludelukelodod.pdfIn PDF document text
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138d16655348---78104216572.pdfIn PDF document text
    • http://gsprojekt.eu/userfiles/files/88249159792.pdfIn PDF document text
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/gdd0kv4njki4nf4i6jnf08dopd/piwetozovabelir.pdfIn PDF document text
    • https://ddtoyz.com/ckfinder/userfiles/files/36386596174.pdfIn PDF document text
    • http://yuqiaohome.com/uploads/files/202109062106024906.pdfIn PDF document text
    • http://semanbio.com/upload/files/tumibejoxivawogope.pdfIn PDF document text
    • https://jooli.ru/ckfinder/userfiles/files/tijiwiduwafeguk.pdfIn PDF document text
    • http://nd-58.ru/wp-content/plugins/super-forms/uploads/php/files/4c16a6c2fda8fd823d6f27be89178d35/30922331842.pdfIn PDF document text
    • http://pekingtogo.com/uploads/files/nosavedorokagobotiwozef.pdfIn PDF document text
    • http://sibmaxi.ru/userfiles/file/fasoxubuvupirefixijix.pdfIn PDF document text
    • http://nsk-nalogov.net/upload/files/fixipebudumorajugewe.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161331f35e39df---55268293679.pdfIn PDF document text
    • https://esteticarcare.com/wp-content/plugins/super-forms/uploads/php/files/75f731361961845c71f280e53b6d5c03/99112824107.pdfIn PDF document text
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613324d125f37---58226300621.pdfIn PDF document text
    • http://carrollcountylawyers.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/lenopevepagikofotemi.pdfIn PDF document text
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/161313d3c3313b---67752623603.pdfIn PDF document text
    • https://thanaclusterwestgate.leaddeehub.com/userfiles/files/diniselixegumiwugedipux.pdfIn PDF document text
    • https://eventaipei.com/upload/files/48777775530.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_off0000adf4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xADF4 10868 bytes
SHA-256: 7437e4b43fa30a0356ae73ff10920e45f6d903353da398b3cb407db4cdeeaf57
font_01_sfnt_off0000c74c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC74C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000df5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF5E 14748 bytes
SHA-256: 45bdbf1aef472f10fd73495c84591f61177f3802987af1c5f17edefa11571c60