Malicious PDF — malware analysis report

Static analysis result for SHA-256 7ca6851b51b17130…

MALICIOUS

PDF

86.5 KB Created: 2021-08-08 17:41:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 81de369aa1a8b4fc8f7982d9e45c2310 SHA-1: 3ddaab7aace3aaeb6cab5de7b29431499530222a SHA-256: 7ca6851b51b17130bba0ffbff85f96b4a419e18c8856f928f923748346c4df77
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to domains flagged as compromised CMS uploads or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the link farm structure itself is the primary attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9919

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://haozuowenwang.com/imagefiles/file/dubawaxumutabufifuwen.pdf In PDF document text
    • http://hzbaoyan.com/images/upload/File/9681097461.pdfIn PDF document text
    • https://bluetact.com/ckfinder/userfiles/files/rikanowarirolor.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a13b806926c---busowogasukonirabomexin.pdfIn PDF document text
    • https://www.parkgest.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160b80030b8c1b---50294141434.pdfIn PDF document text
    • http://iburgisidimarsala.eu/userfiles/files/fawujoriwedodijenuvu.pdfIn PDF document text
    • http://aryajob.com/user_upload/file/80714156085.pdfIn PDF document text
    • http://tuzvedo.hu/elemek/file/guwovapikotax.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/3ce7474c53548fb8f97e1e368092a791/97101267701.pdfIn PDF document text
    • https://orkhaconstruction.com/wp-content/plugins/super-forms/uploads/php/files/4av068bnkqn02pi64kvbq1279i/77079056347.pdfIn PDF document text
    • http://assytekservizi.com/userfiles/files/57048396085.pdfIn PDF document text
    • https://thehamptonsbloomington.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090a3607d8b2---26830506560.pdfIn PDF document text
    • https://forkidsvietnam.vn/wp-content/plugins/super-forms/uploads/php/files/dk47eak9aunpq92rgl60b9ka80/34212332840.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/1606ccba2c09e3---31359016199.pdfIn PDF document text
    • http://frezerovka.by/images/fxeditor/file/bijapupaxewineniruv.pdfIn PDF document text
    • http://fonnepal.org/userfiles/file/81297253220.pdfIn PDF document text
    • http://koszyczarek.pl/userfiles/file/vuwopukagolelaxepelupes.pdfIn PDF document text
    • https://harkakotony.hu/UserFiles/file/71589016193.pdfIn PDF document text
    • https://fajanav.com/aym_image/files/77115734749.pdfIn PDF document text
    • http://cephedanismani.com/images/pages/file/95710990726.pdfIn PDF document text
    • http://uniroll.pl/user_images/file/naniruwekeliforisad.pdfIn PDF document text
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160c2e0cbe1f2f---40719934280.pdfIn PDF document text
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/q54u7rmut1lhkld3vfjojr8e0k/fewiwisurijapipina.pdfIn PDF document text
    • https://www.hermanosvalerorecio.com//ckfinder/userfiles/files/guvoburirukuwolip.pdfIn PDF document text
    • http://akkoryazilim.com/userfiles/file/potanunutegagubomo.pdfIn PDF document text
    • http://voijin.com/userfiles/files/ratugajididafebij.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=partitioning+4+digit+numbers+ks2+worksheetsPDF 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_off0000eadf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEADF 16816 bytes
SHA-256: a9840c44aed260e1d97cf751a347e201c70b18292f5f17ef67cb970e38a0a75b
font_01_sfnt_off000116d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116D2 11264 bytes
SHA-256: d1901ec0b007c891eb22fe82247e81d119f2132443eb6955e28fda05d587e050
font_02_sfnt_off0001310a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1310A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1