Malicious PDF — malware analysis report

Static analysis result for SHA-256 871cff97a5b20367…

MALICIOUS

PDF

92.6 KB Created: 2021-08-10 17:19:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a4165ec1dc0af69e8f11604cff23fe4a SHA-1: 34f149073d87b7bc31bc0656e31e3f7de199723c SHA-256: 871cff97a5b20367f3dd2ac0cf0a2dc0eed4b208e79f780779a89f80ea54b842
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous URLs pointing to compromised CMS upload directories, suggesting an attempt to distribute further malicious content or phish users. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics reinforces this assessment.

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://iamluno.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079d4b5732c8---zebajene.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607beb5d5e62c---mutanopixozanutibejaf.pdf
    • https://www.intermediastudios.com.mx/wp-content/plugins/super-forms/uploads/php/files/2f0f4be3d8007359d5761e287c63bbe7/93567532630.pdf
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/a4c91347b591a15860dfe97f74910eed/biwunelinejosukonipize.pdf
    • http://taikenplan.jp/ckfinder/userfiles/files/gilumaxu.pdf
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/16105ad196d81b---54243410756.pdf
    • http://drironcat.com/images/file/69224121089.pdf
    • http://tavaszitura.eu/userfiles/files/wixifogaxi.pdf
    • http://korea-labels.com/ckfinder/userfiles/files/10208723417.pdf
    • https://areicon.com/images/file/zijemitovuz.pdf
    • http://xn--vb0b83rba554gca.kr/page_data/file/20210722185318.pdf
    • http://plenar.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1607a5c4d285d4---rofarejidopori.pdf
    • https://www.golddustdental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c590afb8f06---linuzemanezarutobanop.pdf
    • http://nkmate.com/FileData/ckfinder/files/20210726_141C2D5DBFDB6F6C.pdf
    • https://securityguardsupply.org/php/uploads/file/97451062672.pdf
    • http://stlnsk.ru/uploads/file/babunazaponevulosuzedo.pdf
    • https://certifiedcollisionrepair.com/home/cert/public_html/ckfinder/userfiles/files/71836984787.pdf
    • https://prokoncept.hu/admin/blogfck/image/file/pibumi.pdf
    • http://safaraval.com/basefile/safaravalcom/files/35104803529.pdf
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b5610d9eb90---34875856862.pdf
    • https://munis-roquesalbes.cat/demo/vilalba/imatges/file/xosirilabawiporu.pdf
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf9ff0ba1c2---71885147312.pdf
    • http://erbilsunhotel.com/wp-content/plugins/super-forms/uploads/php/files/4ki3qeid3gi4ed4edb8ej5jmr4/78532458993.pdf
    • http://loca-granderoue-montaletang.com/ckfinder/userfiles/files/68965665425.pdf
    • http://asdgolfclubtoscana.com/writable/public/userfiles/file/16396592802.pdf
    • https://cometsecurity.in/admin/userfiles/file/57865379610.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=western+union+apk+latest+version+free+download
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fd05.bin
76f8f04fb1694b77a370c171da5e97c86f512d12886b81687b25f4521212691a
pdf-font-stream PDF embedded font (sfnt) at offset 0xFD05 10828 bytes
font_01_sfnt_off0001163b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1163B 16792 bytes
font_02_sfnt_off00012e4d.bin
448cdf12a9c15159ab8896f463cb3dd94bfdbbb41ccfbfcbb575048aaae15da9
pdf-font-stream PDF embedded font (sfnt) at offset 0x12E4D 20300 bytes