Malicious PDF — malware analysis report

Static analysis result for SHA-256 65b62a77a4dfa053…

MALICIOUS

PDF

69.2 KB Created: 2021-10-01 06:33:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 51f85b3342bdf40a1d45d46b41791d08 SHA-1: 23fb804177ba87190684bd8d2a40ce245e79525b SHA-256: 65b62a77a4dfa053989d3dd2f274d4f2d1b6a852da862d34e811334eef71a5cb
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan. Multiple heuristics indicate the presence of link farms pointing to potentially compromised or disposable hosting, suggesting an attempt to redirect users to malicious content. The ML classifier also strongly indicated maliciousness. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with phishing or malware distribution lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://emailreceptionist.net/userfiles/file/dokegud.pdf
    • http://candybeauty.vn/upload/files/pudosimobosi.pdf
    • https://childrencareandliteracysociety.org/userfiles/files/xewumosemovivigux.pdf
    • http://shesob.com/file/files/25986593266.pdf
    • https://optimuselearningschool.com/learning/site/images/uploadfiles/votufu.pdf
    • http://hamdannepal.com/userfiles/file/murugizi.pdf
    • http://gugugroup.com/userfiles/kimakano.pdf
    • http://skidubravy.sk/spravca/ckfinder/userfiles/files/jirixivegem.pdf
    • http://xn--j1aii.su/userfiles/file/gurilobotixobi.pdf
    • http://ablerexthailand.com/userfiles/files/46950122389.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161485e0ce194b---71767919712.pdf
    • http://hanasushi6.com/uploads/files/mukutera.pdf
    • http://inphilong.com/upload/files/9631064260.pdf
    • https://cnn-logistics.com/asset/files/sonujo.pdf
    • http://fgosvo.ru/files/files/migurilofisibirejuteg.pdf
    • http://dailythang.com/userfiles/files/12261964534.pdf
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16141b79c865a2---83428032585.pdf
    • https://doctmcooper.com/userfiles/files/xuvemajubodul.pdf
    • http://sherwoodchambergolf.org/ckfinder/userfiles/files/44025830628.pdf
    • https://podimercrm.com/img/files/95214203644.pdf
    • http://meadescafe.com/userfiles/file/kovubegudetevujemal.pdf
    • http://husplaza.hu/editor_up/25423235260.pdf
    • http://imobilestore.de/userfiles/file/42319303174.pdf
    • https://athensviptour.com/wp-content/plugins/super-forms/uploads/php/files/7155baeee80884b7c658e84d4a20e25f/raniguruzalitubekiw.pdf
    • https://xn----7sbbg1ddpkdc.xn--j1amh/uploads/files/29848457630.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=famous+male+volleyball+players
    • 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_off0000b08f.bin
313c305d95f49c7c4643f667b66e6d49dfedff1d060bc7af6f9b19e04bb499be
pdf-font-stream PDF embedded font (sfnt) at offset 0xB08F 15444 bytes
font_01_sfnt_off0000d7b0.bin
eae809d40f6b82d0b658dfd5f7f087115fa15071967402e6dab72133a740b96b
pdf-font-stream PDF embedded font (sfnt) at offset 0xD7B0 10516 bytes
font_02_sfnt_off0000ef80.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF80 16792 bytes