Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1c3df2e6d912f3b…

MALICIOUS

PDF

88.4 KB Created: 2021-07-14 03:28:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: be93ceca23ee52ac899fbe8b7f94de8d SHA-1: 6dc86cfca68f66b3b85c6a8132c7fa01b7d1419d SHA-256: a1c3df2e6d912f3b3cf4c9ba24efe76459c5db5168698e9cd5c67ad490e2404b
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains numerous links pointing to potentially compromised WordPress sites and disposable hosting, suggesting a phishing or malware distribution attempt. The embedded links are designed to appear as legitimate file downloads, aligning with spearphishing tactics. No scripts were extracted, but the PDF structure itself facilitates the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9822

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://statewideroadservices.com/clients/879378/File/86725381913.pdf
    • https://dutchfansitenetwork.nl/ckfinder/userfiles/files/14755589262.pdf
    • http://bhk-aindling.de/userfiles/files/musamozedimuriwexutojim.pdf
    • https://www.beewellrx.com/wp-content/plugins/super-forms/uploads/php/files/tmp/vupesuxikega.pdf
    • https://syntellect.ru/Repository/file/surixixogabam.pdf
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160910e720be31---bagolanigagek.pdf
    • https://unicornproduction.gr/wp-content/plugins/super-forms/uploads/php/files/7a60a8603be68628f2fa9d6e7e968293/makijez.pdf
    • http://www.ausafrica.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160855a4f5c7fe---29814938843.pdf
    • http://www.playerclub.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160aa12b8813b3---wolazisobosalazegoxe.pdf
    • https://fotoprint.lv/downloads/file/dasazedefivos.pdf
    • https://prikolnaya.com/wp-content/plugins/super-forms/uploads/php/files/e81068cd4869f09cb878aa893579d1d2/wijemidatapajexexubeporu.pdf
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095ffd4c4c42---xuvolo.pdf
    • http://fincasotilloviejo.es/files/sotillo/_repo/file/35427389961.pdf
    • http://zzquansu.cn/d/files/40811573233.pdf
    • http://www.franklinwebdesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160887483dbb19---56044231629.pdf
    • http://bjzjygj.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/delibisojigonusuxule.pdf
    • https://lakeshoresmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/juu6mlk0qgv0jb6hdmva286p20/20238352734.pdf
    • http://madmojo.com/fckupload/file/20420972280.pdf
    • http://sh8ke.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bb23d8a2ca---pupaxutafun.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8e21129b36---wekod.pdf
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/v1e5sdhrdrn96qm0vg9947ua67/87430131384.pdf
    • http://dinskayarealty.ru/media/file/pufefivotov.pdf
    • https://bbpartner.cz/userfiles/file/lotabufilipuwupisik.pdf
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160c4b3e981905---zewab.pdf
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c997bcaacf4---sazazasalen.pdf
    • http://doublehappyvstheinfinitesadness.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080a935dabcb---66819926042.pdf
    • http://allaboutdowney.com/userimages/wupimumi.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=streaming+after+we+collided
    • 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_off0000f0f8.bin
358b5053684af34023091856b32c8ceab17bf24ab88e82a84fec784465c62314
pdf-font-stream PDF embedded font (sfnt) at offset 0xF0F8 10812 bytes
font_01_sfnt_off000109c6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x109C6 16792 bytes
font_02_sfnt_off000121d8.bin
e400f8f9f974af8f3ad52b4b3ede258f46e1f34518eb16eb37d36e3477fa413a
pdf-font-stream PDF embedded font (sfnt) at offset 0x121D8 19304 bytes